psychology Unit 4
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Clinical characteristics of Schizophrenia
Divided into positive & Negative. Positive are in addition to normal behaviours, negative are a reduction. In DSM diagnosis there should be at least 2 or positive symptoms present for one month.
Positive characteristics of Schizophrenia
- Hallucinations- Bizarre unreal perceptions. Could be hearing things, seeing things or feeling things on the body. Voices can talk about person themselves, warn of dangers or give out orders
- Experiences of Control- When a person believes their mind &/or body is being controlled by aliens.
- Delusions: Bizarre beliefs that seem real but are not. Paranoid delusions where sufferer feels they're being persecuted or considered against. Delusions of grandeur: believes they're a famous or important person. Delusions of reference: believes comments even on telly refer to them alone.
- Disordered thinking: Fells their thoughts have been put in or taken out of their mind or that others can hear them. speech often muddled because of this.
Negative characteristics of Schizophrenia
- Affective Flattening- Reduction in amount & range of emotions shown using facial expression, voice tone, eye contact & body language.
- Alogia- Little speech. May also be hard to follow word repeated or made up.
- Avolition- Reduced desire to do anything goal directed. People spend entire days doing nothing.
Reliability of diagnosis of Schizophrenia
- Different criteria used
- Use of different tools to diagnose schizophrenia
Schizophrenia diagnosis reliability: different criteria used
- Little consistency in how people have been diagnosed over years. So indiscriminately in 1950's that it was reduced to being a label for nay mental disorder
- Kurt Schneider (1959) identified a group of symptoms of SC rarely found in other disorders. 'First rank symptoms' saw them as being valuable diagnosis for SC. Form basis of current ICD-10 classification.
- DSM 111 in 1980 was designed for much more reliable method of classifying psychiatric disorder. In a review Carson said it had solved the problem. Still little evidence 30 years later it's used in a reliable way be psychiatrists. Whaley 2001 found inter rater reliability of diagnosis of schizophrenia is as low as 0.11
One being sane in an insane place study Rosenhan 1973
- Supports unreliability of diagnosis of SC
- Eight normal people presented themselves to psychiatric hospitals in US claiming they heard unfamiliar voices in their head saying words 'empty' 'Hollow' and 'Thud'.
- Only lie after behaved normally.
- All diagnosed with SC & admitted.
- Through stay non of the staff recognised they were normal.
- Follow up study Rosenhan warned hospitals he's send out more 'Pseudo Patients'. Resulted in decreased detection rate of 21% but no more pseudo patients.
- Show unreliability of diagnosis & how once somebody is labelled all their behaviours & characteristics are coloured by that label.
Reliability in diagnosing Schizophrenia: Use of different tools
- Number of different tools used by doctors to diagnose.
- Major systems ICD10 & DSM TR IV are very similar in classification. Improves reliability but not identical.
- ICD more emphasis on 'first rank symptoms.'
- DSM requires symptoms to be in place for 6 months, ICD only 1.
- Other tools available to help St Louis criteria
- Confusing makes it difficult for Clinicians to agree precisely what they mean by SC.
- Shows definition of mental disorders are arbitrary & liable to change.
- Dangerous if wrongly diagnosed can lead top tragic outcomes
- Led to cultural difference. US diagnosis more common. Copeland et al 1971 gave a description of a patient to 134 American and 194 British psychiatrists. 69% of Americans diagnosed whereas only 2% of British gave same diagnosis.
- Critics of diagnosis say it's a problem labelling a patient with SC.
- People labelled may conform to label therefore becomes self fulfilling prophecy.
- Stigma can lead to prejudice & suffering because of ignorance.
- Several films show Schizophrenics as aggressive violent & evil which encourages misunderstanding.
Validity in diagnosing Schizophrenia
- Symptoms often overlap with other disorders
- Variability of symptoms
- Cultural variations
Validity of diagnosing Schizophrenia: Symptoms often overlap with other disorders
- Difficult to define SC symptoms often overlap with other disorders e.g. Mood disorder & autism.
- Some prescribed & recreational drugs can cause psychotic behaviour
- Sometimes patient may have more than 1 disorder e.g. depression often co-morbid with SC
- Such examples show how important it is for clinic to carry out thorough physical examination & careful history taking to make diagnosis.
- ICD & DSM have tried to address this by giving mixed disorder categories such as post-psychotic depression, validity of these categories have been questioned.
Validity of diagnosing Schizophrenia: Variability of symptoms
- people who have SC have different symptoms, responses to the treatment & possible causes.
- Led to suggestion SC is not a single disorder & various sub types have been suggested
- Validity of sub types questioned e.g. People who have undifferentiated SC are re-categorised when other symptoms develop
- British psychiatrists prefer to use overarching diagnosis of SC & only use sub categories when there's close correspondence to criteria.
Validity in diagnosing Schizophrenia: Cultural variations
- Although SC is in all cultures it's a consistent finding it's diagnosed more frequently in African Americans & African Caribbean populations.
- Not clear whether this reflects greater genetic vulnerability, problems with being part of minority group or misdiagnosis.
- Could be clinicians misinterpret cultural differences & expression as symptoms of SC.
Biological explanations of SC
- Twin studies
- Family Studies
- Adoption studies
- Biomechanical Factors:
- Dopamine Hypothesis
- Brain damage:
- Enlarged Ventricles
Genetic Explanation of SC
- Twin Studies:
- Most twin studies have found much higher rates of concordance in MZ twins than DZ.
- Joseph (2004) calculated that in studies prior to 2001it was 40% for MZ twins & 7% for DZ
- More Recent, methodologically sound studies
- where researches don't know if MZ or DZ
- lower concordance rate for MZ but still many times higher than DZ concordance rate.
- Family studies:
- SC seems to run in families controlled studies (Gottesman 1991) have shown risk is in proportion to amount of genes shared.
- Children with 2 affected parents risk is 46% with one parent is 17% for grandchildren is 5% & general population risk is 1%
- Adoption Studies:
- Difficult to make conclusions where genes & environment are the same studies are done on adopted people.
- Kety et al (1988) Denmark found in adopted children who developed SC 14% had biological relatives with disorder, only 2.7 of adopted relatives had SC.
Evaluation of Genetic explanations of Schizophrenia
- Twin studies don't always use same criteria. Different definitions produce different concordance rates & different methods used to distinguish MZ & DZ twins
- MZ twins rare only 1% get SC so small sample size
- High concordance rate could be found in MZ twins cause they tend to be treated the same
- Some get SC that have no close family with disorder genes can't be only explanation
- Could be SC is caused by large number of genes not just 1 so it's only when large number are present that symptoms occur
- May be genes don't cause SC but predispose (place someone at greater risk of getting it.)
- Likely there's a genetic component in SC but any pattern of inheritance is likely to be complex.
Biochemical Explanations of Schizophrenia
- Dopamine Hypothesis:
- Dopamine Neurotransmitter in brain.
- Schizophrenics thought to have high amount of D2 at certain synaptic sites
- Thought to have abnormal high number of D2 receptors results in more D2 binding & therefore more neurons firing.
- D2 plays key part in attention, problems with attention found in sufferers so supports view.
- 3 Main sources of evidence for D2 Hypothesis:
- Amphetamines (Stimulant drugs)-increase availability of D2, can induce symptoms of acute paranoid SC in unaffected individuals.
- Antipsychotic drugs-Block activity of D2 to brain. Very effective in reducing some major symptoms of SC such as Hallucinations & Delusions. Strengthens case of D2 being important factor in disorder
- Parkinson's Disease-Low levels of D2 found in sufferers. When people take L-Dopa to increase levels sometimes suffer from SC type symptoms.
Evaluation of Biochemical explanations of Schizophrenia
- Post mortems:
- Post mortem examinations on people with SC show increase of D2 in brain (Seeman 1987).
- Post Mortems usually carried out on people taking drugs to cure SC for years. Difficult to know if increased D2 is result of drug therapy rather than cause of SC
- Haracz 1982 found patients taking antipsychotic drugs shortly before death had high D2 levels & those not taking drugs had normal levels.
- PET Scans:
- Wong et al 1986 found density of D2 receptors in Schizophrenic patients was twice that of people who had been treated with drugs & a control group. However not been replicated
- Drugs don't always work:
- Drugs don't work for everyone diagnosed. also only tend to remove positive not negative symptoms. Different types of SC may be different types have different causes.
Brain damage explanations of Schizophrenia
- Enlarged Ventricles:
- Research has found many SC sufferers have enlarged ventricles (cavities in the brain that contain nutrients for the brain).
- Torrey 2002 said on average 15% bigger than normal.
- Those who have this problem tend to display negative rather than positive symptoms & poorer responses to antipsychotic drugs.
- Possible enlarged ventricles are result of poor brain development or damaged tissue which results in disorder.
Evidence of Brain damage in Schizophrenia
- Support other studies have shown those who have type 2 SC have reduced brain matter may relate to brain damage.
- Results far from consistent & difficult to interpret. Meta-analysis of 90 CT scans showed much overlap between schizophrenic & normal ventricle size. Possible reason for larger ventricles may be medication. Study by Lyon et al found as dose of medication increased so did size on ventricles.
- Because these abnormalities aren't found in everyone with SC Crow suggested two types of SC with different causes. Type 1 genetic & associated with dopamine dysfunction. Type 2 shown by negative symptoms may be due to problems at birth or while baby is in womb. Oversimplification as people with SC can show both types & 1 type can develop into other.
Overall evaluation of Biological explanations of SC
- Convincing but as so many different types of SC likely different types have different causes.
- Seems likely it's a brain disorder but processors have not been fully identified yet.
- No study shows 100% concordance rate in twins so other social & psychological factors must be important.
Psychological explanations of Schizophrenia
- Double bind theory
- Family Relations:
- Double bind theory
- Schizophrenic mother
- Expressed emotion
- Life events of Schizophrenia
- Behavioural explanations
- Psychodynamic explanations
Family relationships explanations of Schizophrenia
- Double bind theory (Bateson et al 1951):
- Suggests children who later become schizophrenic are put in a 'double-bind' or 'no win' situation.
- Happens when they're given contradictory messages from their family. E.g. mother tells child she loves them but turns away from them at the same time.
- Child doesn't know how to respond as one message cancels out other. Whatever they do will displease parents & as a result they may confused & suspicious that can start disorder.
- Support of this Berger found schizophrenics reported a high number of no-win statements by their mothers than non schizophrenics. May not be reliable as patients recall may be affected by their disorder. Other studies have found no difference in amount of contradictory messages in families with or without a schizophrenic person.
- Schizophrenic mother Reichman 1948:
- Used to describe mother domineering & insensitive. Actions contradictory express love & care but critical at same time. Led to confusion & child withdrawing from normal communication.
- Schofield looked at 178 patients with schizophrenia who were treated at AMerican Hospital. Given in depth interviews regarding childhood traumas, maternal characteristics & relationship with parents. 150 non patients matched for education, social class & marital status received same interview. Found almost no difference between groups. Patients with SC were less likely to report childhood trauma, poverty, abuse or divorce. Only difference quality of mothering. Mothers of patients less likely to be affectionate & more domineering & overprotective. Later studies found little evidence of this type of mother & effect she's supposed to have. Largely abandoned in 1970's as genetic & chemical explanations made blaming the mother unnecessary.
- Expressed Emotion:
- EE is a style of communication that involves criticism, hostility & emotional over-involvement. Brown et al 1966 looked at progress of schizophrenic patients discharged from hospital. 58% who returned to high EE families relapsed compared to 10% going back to low EE families. EE received much more universal scientific report than Double bind theory however unclear whether EE is cause or effect. Has led to effective therapy where families are taught to reduce EE & this has led to lower relapse rates.
Evaluation of Family relationships explanations of Schizophrenia
- May be effect of illness rather than cause. Studies of families usually occur after disorder & therefore family relationships will have been altered by having ill son or daughter.
- If family is at fault all children in the family should develop disorder.
Life events explanations of Schizophrenia
- One suggestion is sufferers have had number of big stressful life events e.g. death of close relative. May cause high arousal which leads to neurotransmitter changes
- Brown & Birley 1968 found 50% of people experience a major life event in the 3 weeks before a schizophrenic episode, only 12% had in 9 weeks before that. Control group had few life events in same period suggesting life events triggered the relapse.
- Not all evidence supports role of life events. Van Os et al 1994 found no links between life events & onset of SC. Patients equally likely or not to have had major life event in 3 months prior to illness. Evidence is correlational. Illness may be cause of life events rather than effect.
Behavioural explanation of schizophrenia
- Faulty learning through operant conditioning. Punishment or neglect may lead the child to withdraw & consequently they are labelled as 'odd'.
- Bizarre behaviour rewarded with attention & this positive reinforcement encourages them to conform to the label.
- Behaviour becomes a self fulfilling prophecy & is more exaggerated until it's labelled as SC.
- Rosenhan 1973 supports view that once labelled diagnosis continues to influence how staff see patients. In study when people pretending to have SC were writing down events it was reported as excessive note taking.
- Has some face validity but more relevant to maintenance rather than cause of disorder as doesn't explain how bizarre behaviours originate or account for severe cases.
- Some feel it draws attention away from real & disabling symptoms of SC. Kimble et al 1980 said of a patient "He had his finger up his bottom to keep his thoughts from running out, he tried to tear out his hair because it really belonged to his father & this man was telling me he did this because someone had labelled him as schizophrenic."
- Some success has been reported in behavioural therapies where patients have been taught useful social skills.
Psychodynamic explanations of Schizophrenia
- Is world is particularly hard Freud (1924) said you might regress back to a stage of development where ego had not separated from id, primary narcissm.
- Ego rational part of mind so lack of ego development results in egotism & loss of contact with reality.
- SC seen then by Freud as infantile state & some symptoms reflect this e.g. Delusions of Grandeur.
- Others such as auditory hallucinations reflects persons attempt to re-establish ego control.
- No research evidence to support. Theory based on Austrian Women so population validity low. Now dated so lack temporal validity.
History of treatment of biological therapies for SC
Until 1950's treatment fairly primitive. Sufferers institutionalised in grim, often overcrowded mental hospitals. Often restrained in straight jackets & some cases objected to lobotomy- surgical procedure to disconnect parts of brain. No evidence this helped people in many cases causes severe mental & emotional damage.
Drug therapy- Antipsychotics for Schizophrenia
- Conventional antipsychotics-Used primly to combat positive symptoms. Thought to be caused by too much D2. Reduce effects of D2. Called antagonists bind to D2 receptors but don't stimulate them so block action. Effectiveness in reducing symptoms such as hallucinations & delusions has led to Dopamine hypothesis.
- Atypical antipsychotics-Also combat positive symptoms but claimed they have some positive effects on negative symptoms too. Also block D2 system but thought to block serotonin receptors in the brain too. Help by temporarily occupying D2 receptors & then rapidly disassociating to allow normal D2 transmission. Fewer side effects cause of this such as tardive dyskensia (involuntary movements of tongue & mouth).
Effectiveness of Drug Therapy for Schizophrenia
- Less people in institutions - Many studies show these drugs are effective in controlling positive symptoms & allow people to live outside an institution. Continued use of drug at low dosage has been helpful in preventing relapse.
- Lower relapse rate-Many studies have shown effectiveness of drug by comparing relapse rate of those on medication with those on placebo. Expected it would be lower if drugs works & this is what's been found.
- Conventional (Don't work with negative symptoms)- Conventional antipsychotics don't work with negative symptoms can return- Reduce symptoms of SC but symptoms often return if medication stops
- Don't always work- Drugs aren't effective for everyone with SC. About 30% don't respond to these drugs or are intolerant to them. Means minority of people with chronic SC can't be helped with medication.
- Are Atypical better?- Although introduction of atypical raised expectations about superior drug to conventional meta-analysis of studies comparing them found only moderate improvement. Claim they are more effective with negative symptoms has very marginal support.
- Symptoms can return
Appropriateness of drug therapy for SC
- Side effects: Conventional drugs can produce distressing & sometime irreversible side effects. Minor side effects: Drowsiness, dryness of the mouth & changes in weight & depression. More serious-Tardive dyskensia uncontrollable lip & tongue movements & facial tics. Irreversible in 75% of cases.
- Improvement of Atypical antipsychotics: Atypical drugs seem to have fewer side effects than older drugs. Tardive dyskensia rates lower in atypical 5% as opposed to 30% after 9 months of treatment means people more likely to continue taking.
- Ethical issue-Unpleasant & irreversible: Side effects raise issues of whether drugs should be used at all. US large out-of-court settlement was awarded to tardive dyskensia sufferer on basis of human rights.
- Ethical issue-Right to not take medication: Unpleasant side effects means patients sometimes stop taking medication. leads to patients relapsing & returning to hospital. Combat this patients sometimes given injections of long lasting drugs, takes away option to stop taking tablets. Criticised for taking control away from individual.
- Medication sometimes too high: Regulation & Monitoring of drugs important. Found doses of medication sometimes too high because have not been reduce to maintenance level once acute stage is over. Sometimes difficult to gauge dosage. Some don't require medication after acute stage, some quickly relapse without it.
ECT on SC
- Originally used because it was thought SC was rare in people who have severe epilepsy.
- Procedure: Electrodes placed on patients head-either non dominant side or both sides. First receive anaesthetic & something to paralyse muscles. Oxygen given to patient & small amount of electric current lasting about half a second is passed through brain until seizure occurs. Usually given 3 times a week with patient receiving between 3-15 treatments.
- Effectiveness: Tharyan & Adams 2005 looked at 798 patients & found people improved more with ECT than placebo ECT. No evidence that this was maintained in the medium or long term. Also evidence when combined with medication it resulted in even greater improvement. However other studies have found no greater benefit than medication & no difference than placebo ECT.
- Appropriateness: Because of risks of ECT including memory loss, brain damage & even death use of ECT fro SC has declined.
Psychological therapies for SC
- Before antipsychotic drugs psychotherapy not considered appropriate for treating people with SC. Most patients detached from reality & would not have been able to cope. Now Psychological therapies are used alongside drugs.
- Family interventions
- Psychodynamic therapy
- Cognitive behavioural therapy (CBT)
- Social interventions
Family interventions for SC
- Type of communication in family can influence maintenance of SC.
- One treatment aimed at reducing the amount of expressed negative emotion in the family needs involvement of several family members as well as patient.
- Involves some education where family members are given info about disorder & ways of managing it e.g sharing info, less expressed emotion, adjusting expectations & expanding social networks.
- Family also trained to recognise early signs of relapse so they can respond quickly & reduce effects.
- Evaluation- effectiveness & appropriateness: Meta-analysis found family interventions were very effective in significantly reducing rates of relapse & of admissions to hospital of patients. Improves taking of medication. Study showed range of outcomes clearly most suited to those who still live with or have close contact to families.
Psychodynamic Therapy for SC
- Many psychoanalysts thought it was impossible to use psychoanalysis because patients couldn't form transference with therapist. Other forms of psychodynamic therapy found to be successful. Aim to replace harsh & punishing conscience with less destructive & more supportive one. As patient gets healthier they take more active role in own recovery.
- Effectiveness: Meta-analysis looked at 37 studies & over 2 and a half thousand patents & found 66% of those receiving psychotherapy improved after treatment compared to those who didn't receive it. Found both psychotherapy & CBT produced similar levels of benefit & results showed no difference if patients had medications as well or not. Found outpatients did better than inpatients. Some argue it's impossible to draw conclusions for/against this therapy. Others suggests over stimulation provided by this longer hospitalisation develop more symptoms & are more likely to refuse further treatments.
- Appropriateness: Expensive & treatments usually long term. Some argue as it doesn't seem any more effective than drugs it isn't worth extra expense. Evidence money may be saved as people using it less likely to be in mental hospitals & more likely to be employed.
Cognitive behavioural therapy for SC (CBT)
- Based on idea people with SC have irrational & unrealistic ways of thinking. Goal is to challenge & Change patterns & alter beliefs.
- Chadwick et al 1996 a man thought he could make things happen simply by thinking them. Shown paused video recordings & asked what happened next. In over 50 trials didn't get 1 right & understood he didn't have power to influence events.
- Type of CBT Belief modification teaches stratergies to counter hallucinations & Delusions. Taught to see delusion & Hallucinations as hypotheses rather than reality then learn to challenge initial thoughts.
- Behavioural stratergies taught in CBT include relaxation techniques, breathing exercises or ways of drowning out hallucinations by shouting or turning up TV. At least 37% reported stratergies successful in managing their symptoms.
- Supporting research- several controlled studies have shown CBT effective in treating SC. Turkington et al 2000 found it had a significant effect on both positive & negative symptoms & could be delivered effectively in brief programme by community nurses. other studies have shown there are lower patient drop-out rates & greater patient satisfaction with treatment with CBT is combined with Antipsychotic medication.
- Many studies conducted where patients are also receiving drugs. Impossible to judge effectiveness of CBT on its own.
- although some studies show improvement CBT does not offer a cure but a way of normalising symptoms. Commonly believed in psychiatry that not everyone with SC would benefit from CBT because it's thought they wouldn't engage with the therapy. Found to be case particularly with older patients.
Social interventions for SC
- Some evidence social factors effect SC. Makes sense to use social strategies to help relieve symptoms.
- Stimulating environment:
- Wing & Brown 1970 compared female in patients on a range of positive & negative symptoms. Found marked differences in negative symptoms between those women that were on wards which were stimulating & those that were not. Result replicated in number of number of studies & influenced hospitals & day care centres to provide environments that are stimulating, promote self esteem & personal control.
- Social Skills Training SST:
- Uses various techniques such as modelling, role play & reinforcement. Active therapy & can teach a range of verbal & non verbal skills such as self-care, conversational skills, management of own medicine & coping with stress.
- Results of intervention generally positive but seems likely gains are not always continued after programme has finished so approach seems to work better when combined with other therapies. Critics say it doesn't generalise well to real life situations. However research has shown that such programmes are helpful & patients on medication & SST adjust to living in the community better & avoid rehospitalisation better than other groups on medication & SST alone.
What is anomalous experience?
- Something that can't be explained by science:
- Out of body experience: sensation of floating outside your body
- Near death experience: Sensations experienced when close to death often interpreted as glimpse into the afterlife.
- Spontaneous psychic ability (PSI): Extra sensory perception e.g. Telepathy, clairvoyance or psychokinesis.
- Anomalous healing: Healing through unexplainable methods e.g. spiritual.
Two main approaches to paranormal
- Parapsychology: Believes paranormal exists & tries to prove this
- Anomalistic psychology: Believes paranormal activities can be explained through psychological & Scientific means. Are opened minded to evidence it does exist
What is a science
Replicable, falsifiable (Able to be disproved), Allows precise controls of variables, Uses scientific processors (Clear testable hypothesis),peer review, Objectivity (Not personal).
Is Parapsychology a pseudoscience?
- Some researches say parapsychology is a pseudoscience- a field of science that pretends it's a science but lacks important characteristics e.g.
- Lack or replicability
- Lack of falsifiability
- Lacks ability to change
- Reliance on eye witness testimony
- Avoidance of peer review
- Use of jargon instead of precise terms
- Lacking a theory
Parapsychology not replicable
- Many studies of parapsychology are not well controlled & have failed to be repeated. If study is replicable & results not confirmed puts original study in doubt.
- Freud says this lack of repetition is what separates parapsychology from established sciences.
- particularly suspicious if success is produced by small band of believers while replications meet with failure.
- Other parapsychologists have said it's false to think research should always have significant results- some failures to replicate could be due to researchers designing studies that were too small to measure the effects they were dealing with.
- Some paranormal psychologists say that because spectics are present the phenomena disappears - the phenomena are jealous
parapsychology not Falsifiable
- Aim of science is to test hypothesis.
- Not possible to prove hypothesis correct but should be able to prove it wrong. some cases in this field it's not possible.
- Study may find not evidence of reading someone's mind. Would appear to prove it doesn't exist but is not accepted by believers.
- Cottingley Fairies picture lacked falsifiability it's hard to prove photo was fake. Also true for UFO's & Hauntings.
- Photograph regarded as definite proof fairies existed.
- 5 Photos taken between 1916 & 1920 by cousins Elsie Wright & Francis Griffiths who lived in Cottingley.
- Girls claimed to play with fairies, nobody believed them until photos.
- Various attempts to prove photos fake failed until 1983 when they admitted hoax.
parapsychology lacks ability to change
In Science explanations are adapted as a result of hypothesis testing. Not case with paranormal phenomenon which have continued to be explained the same way for centuries despite lack of evidence.
parapsychology has excessive reliance on personal experiences.
Anecdotal evidence & personal experiences are often main evidence of those arguing in favour of the paranormal. Such reports powerful influence & enough evidence for some people. Hard to replicate. Best way to test is by subjecting them to double blind, randomized, clinical trials & this has not usually been done.
parapsychology avoids peer review
Peer review important mechanism in quality control within science. Pseudo science often prefer to avoid peer review by publishing in books, magazines or even directly on internet.
parapsychology Uses jargon instead of precise terms
Many supporters of paranormal especially those promoting new age therapies such as psychic healing use scientific sounding words such as 'vibrations', 'energy field' & 'harmonisation' in ways that bear little resemblance to precise meanings used by scientists.
parapsychology Lacks a theory
Aim of scientific research is to conduct theories. Most paranormal phenomena have not yet been given theoretical explanations. E.g. How exactly does ESP happen or why some people can move objects without touching them.
Commentary on the scientific status of parapsychology
- Still some similarities: Some areas of paranormal research use similar methods to scientific research. Both gather data, both have a research question on which hypotheses are based, and test the hypothesis.
- Paranormal research not the only example of pseudoscience: Not fair to suggest paranormal research is the only type of psychology which is a pseudoscience: Some accusations have been made on Freud's theory because many of his hypotheses are falsifiable. Many examples of conventional science when believers continue to believe despite disproof. E.g. discovery of cold fusion was shown to be due to poor methodology but there are still researches investigating the topic.
- Fraud: Research has been blighted by cases of fraud where scientists have deliberately deceived people. People who believe in paranormal experiences are more likely to miss the tricks of the fraudsters as they are biased towards results that fit in to their own beliefs.
- Summary: Boundaries between science & pseudoscience are not clear. Because of lack of scientific rigour some would regard parapsychology as a pseudoscience & fraudulent activities of some researches puts even more pressure on those trying to do serious work. Important to continue research as some people make money out of unfound claims, as society we should ask for evidence rather than believe trends or superstitions which in the past have resulted in execution of 'witches' or punishment for mentally ill & research may lead to valuable discoveries e.g. acupuncture now accepted as useful therapy for pain relief due to research that's shown replicable results.
Methodological issues relating to the study of paranormal cognition.
- ESP: Refers to perception of objects or events without any of the senses being involved.
- Ganzfeld studies
Methodological issues using cards
- Early days of ESP testing Zener cards used. Each pack consisted of 25 cards 5 of each design. Cards intended to be emotionally neutral. 'Sender' views each of the cards in the pack and 'receiver' guesses symbols. In order to show ESP person must get more then 5 right, 5 being level expected by chance.
- Risk of bias through shuffling/Using playing cards: Playing cards replaced by Zener cards as thought to be more neutral & therefore less likely to give rise to bias. Early studies manually shuffled open to criticism so in later studies mechanical shufflers were used.
- Experimenter bias: Early studies criticised for experimenter bias, over time improvements made to improve control. e.g. person looking at cards might make subtle changes in posture or breathing or may be wear & tear marks on back of cards used more often which participants could learn. Later became important to reduce barriers that effectively ruled out cheating so that participant & experimenter were separated by screens.
- Concern about ecological validity of work which seemed quite sterile & unlike the kind of spontaneous experiences of ESP that people actually reported & other types of research became more common.
- Procedure: 2 participants 'receiver' & 'sender'
- 'Receiver' typically isolcted in red-lit room with halved table tennis balls over eyes & earphones playing white or pink noise for up to 30 minutes to cut out sensory information.
- 'Sender' is in another room & thinks about a picture randomly selected from four other pictures. Sender concentrates & tries to mentally send information about the image to the receiver.
- During 30 minutes receiver is encouraged to speak out loud describing what they can see, this is recorded by experimenter.
- After this receiver removes headphones & balls & is given set of images & asked to what degree they think each picture was the target.
- If highest rating is awarded to target it's a hit. Expected hit rate by chance should be 25%.
Methodological flaws in Ganzfeld original research
- Honorton 1974: developed Ganzfeld technique & found success rate of 38% however findings were challenged by Hyman 1985 who claimed studies were flawed.
- Lack of control: Lack of control in original studies may have affected results. E.g. poor soundproofing of receivers room would mean when videos were used these could be heard by receiver. also order of presentation often the same can cause bias as there's a bias towards selecting first one displayed.
- Statistical tests: Different studies different ways of being analysed allows researches to conduct range of tests but only report ones that 'worked out' giving false impression on how positive results have been.
- File-Drawer effect: Hyman concerned about file drawer effect where unsuccessful studies are filed away. Means published work tends to be skewered towards successful studies. Researcher's beliefs influence what is left in or out.
- To resolve differences Honorton & Hyman produced a new technique which used computers & video clips to reduce human bias for better controlled studies called autoganzfeld. They said there should be:
- Strict security precautions against sensory leakage.
- Proper randomisation of targets used in ESP
- Advance notice of whether test is pilot study or actual experiment. Experimenter might be tempted to include or not include results from a pilot study depending on whether they back up their hypothesis
- Make clear status of statistical tests. If data has been analysed in several different ways to obtain a significant result needs to be taken into account as weakens evidence.
- Full info given of experimental procedures essential for replicating a study.
Criticisms of Ganzfeld technique itself
- Experimenter effects: technique involves receiver describing image that's being sent. Often wordy & may involve different images. Independent judge has to match reported image to images that were sent, clearly subjective. Evidence of researcher bias founf. Sceptical researchers did not encourage receivers to elaborate their images whereas interviewers who believed did which led to more positive PSI results.
- Sheep-goat effect: people who believe in psi are called sheep those who don't are goats. Evidence from 1000 ppts show sheep tend to score above chance whereas goats tend to show negative results. Clear beliefs of ppt as well as researchers beliefs affect results.
- Non consistent: If psi exists why are ppts right 100% of the time.
- Criticisms by Susan Blackmore: Did a person critique of the Ganzfeld experiments carried out by Carl Sargent in his Cambridge labs. After visiting them Blackmore believed Ganzfeld experiments were open to fraud & error in many ways & she observed first hand several errors & failures to follow protocol. E.g. Sargent Seemed to randomise at times when he shouldn't have, implying researcher bias. Her conclusions were his highly acclaimed academic papers exaggerated evidence for ESP. Significant as many of Sargent's Ganzfeld experiments were included in meta analyses mentioned in the support of reliability & validity of research into ESP. After initially denying Blackmore's claims, Sargent did nothing to address her concerns & failed to allow others to look at his data.
- Summary: Later research has tried hard to reduce problems of bias & some studies have found small psi effect. Methodological weaknesses continue to dog research in this area & most researchers remain sceptical.
- Movement or manipulation of objects without any physical contact
- Two types:
- Macro PK-Effects are noticeable to the human eye includes moving furniture & bending metal spoons
- Micro PK- Involves small changes only shown through statistical analysis for example asking volunteers to come up with more heads than tales on coin flips.
How is PK studied?
- Random event generator is often used to investigate micro PK. REG is kind of electronic coin flipper that produces equal number of heads & tails. Micro PK is shown by asking volunteers to influence REG by coming up with more heads than tails or vice versa.
- Researchers also look at other random events Stevens et al 1998 did an experiment using the internet where ppts were asked to influence the activity of a split beam laser. Comparison was made between experimental group who tried to change beam & those in control group who did nothing. Laser output was more active in experimental condition.
Methodological Problems relating to psychokinesis
- Problems with using dice
- Studies difficult to replicate
- Experimenter effects
- Results can be faked
- Lack of ecological validity
- Effect of expectation
- Decline in results
Bias in dice throwing-Early studies
- Some of the earliest studies of Macro-PK studies were conducted by J B Rhine in 1930's
- Researchers would see if the fall of a dice could be influenced by the mind.
- Die number is chosen & person 'wills' number to appear face up
- If this is more than is expected by chance this is taken as evidence of PK.
- Throwing dice introduces bias:
- Throwing by hand- Skilled dice throwers can toss die in a way which increases the chance of certain numbers appearing face up.
- Different weight of faces- Not every face of die is equally likely to fall face up, most dice bias in the way they're made. E.g. dice has hollows to show numbers so 6 is much lighter than others. Over many throws this becomes significant.
- AO2 (Attempts to overcome problems)
- Rhine invented dice throwing machine & improved methodology by introducing control conditions for comparison where dice would be rolled without PK influence. Found results not as impressive as those of ESP, only occasionally showing slight paranormal evidence.
Psychokinesis difficult to replicate
- Many psychics & mediums have refused to be tested under properly controlled conditions or been unable to replicate their skills when tested.
- Uri has performed all over the world bending spoons & metal objects & stopping the movement of clocks.
- Suggested work is fraudulent as unable to replicate these skills when tested under controlled conditions
- E.g. Jimmy Carson's Tonight show. On recommendations on James Randi he was presented with various tests. In front of millions of viewers he was not able to perform the tasks given to him stating he 'did not feel strong' and 'needed more time.'
- As far as Randi was concerned this was evidence he was a fraud. If his abilities were real he should've been able to perform them regardless of the situation.
- Other critical accounts come from his friend who was often used as a confederate in the audience & the psychic power he claims seems to be increasingly questionable.
Psychokinesis experimenter effects
- Appears particular researchers are more likely to report positive results than others.
- Explanation is subtle way researchers communicate to ppts demonstrated by horse clever hans.
- Owner claimed to have taught the horse arithmetic problems by tapping his hoof on the ground.
- In 1904 scientific commission convinced horse possessed extraordinary powers.
- One sceptic observed horse could only do these things if owner asked questions because he gave cues.
- Similar effects have been observed in PK research where significant result disappeared when experimenter was changed.
- One was of overcoming experimenter & ppt bias was development in 1970's of a machine that could produce truly random events. Lately computers used to produce random events Advantage is they eliminate ppt bias & errors in the recording of the events & checks can be made to show they really are producing random events.
Psychokinesis lacking ecological abiltiy
Some researchers have criticised Random event generators (REG) research on the grounds of ecological validity. Early studies of macro PK involved seeing an object moving & REG is about unobservable changes. It may be that PK doesn't work at the unobservable level.
Psychokinesis can be faked.
- Validity of PK research is challenged because magicians are easily able to do the same things.
- Project Alpha: In 1980 Randi arranged hoax in an investigation which he called project Alpha. Had 2 amateur magicians present themselves for testing to the McDonnell Lab for psychical research in Washington claiming to possess psychic powers.
- Managed to fool scientists for 4 years through more than 160 hours of experiments where they performed standard magic tricks. Deceptions carried out in relatively simple way but at no time were they caught cheating. Researchers described them as gifted psychic subjects. Shows how easy it is for people like Uri Geller to use standard magical techniques to persuade people of supernatural powers. Also shows how important it is for scientists to employ services of skilled conjuror if one wishes to expose fakes.
- Ethics: Although this involved deception & would've been unlikely to be passed by the BPS, Randi & his colleagues were not psychologists & it is hard to see how the point could've been made in any more ethically acceptable way.
- Nina Kulagina: A Housewife who showed her abilities to Western societies to make objects move or make frog's heart beat faster or slower or even stop. Photographed levitating items but it emerged later that often items wre attached by a thread to her leg. When studied it was always In her home or in hotel rooms. This was because each session needed several hours 'preparation'. Although her claims can't be entirely dismissed since no proper testing was done, her abilities could be explained in terms of simple conjuring techniques.
Decline in result of PK
Bierman analysed a large number of paranormal studies conducted since the time of J B Rhine including micro PK studies. Concluded a decline in the effect. Usually if there's a real effect the size becomes greater over time as scientists are better able to identify & control extraneous variables. Here control has led to opposite effect suggests effects are not real.
Effect of expectation
Wiseman & Greening 2005 showed this in a study where ppts were shown a video where a fake psychic placed a bent key on a table. In one condition they heard him say the key was continuing to bend. These ppts were more likely to report further bending than the ppts who had not heard that said.
Use of meta- analysis/ File draw effect
Many published studies of PK are meta analysis. Use of these has many pitfalls. E.g. effect may be magnified by a few flawed studies showing extreme success. Also 'file-drawer effect' where non-significant findings are filed away & not made available.
Summary of PK
Most recent meta-analysis was by Bosch et al 2006 he found a small but significant effect for PK. Most psychologist not convinced & remain sceptical that these studies provide convincing evidence for PK. Effect is so small even a slight methodological flaw could produce it. Most scientists need a higher standard of proof than the weak effects that have been observed.
Personality factors underlying anomalous experience
- Extraversion (opposite of shy)
- Locus of control
- Honorton et al were particularly interested in extroversion as they noticed that in many previous studies extroverts tended to score higher in ESP tasks. They conducted a meta-analysis of 38 studies on ESP & personality & found that extroverts scored higher than introverts in 77% of the experiments. If tests were given to a group of people rather than individuals this difference disappeared.
- Possible explanation is that extroverts respond better to new stimuli then introverts so are more open to paranormal experiences.
- While this shows moderate support for link between personality type & ESP there are questions about how far these results can be generalised as they experiments were very artificial & lacked mundane realism.
- Also extraversion might not be the only reason for the results. It's possible that those who take part in experiments are better at adapting to new situations & are more relaxed.
Locus of control
- People who have an external locus of control think that life is controlled by factors outside themselves e.g. luck and there's very little they can do to change it. Research had consistently shown a correlation between external locus of control & paranormal belief.
- May be that having belief can give an illusion of control or order in an uncertain situation which can reduce anxiety. Residents living in areas of threat during the Gulf War scored higher on measures of magical thinking than those in areas not under threat. Other research found that levels of superstition increased following work on an unsolvable puzzle, but decreases after a solvable puzzle.
- Research has shown this depends on type of paranormal belief. May be that some types such as superstition correlate positively whilst some such as PK correlate negatively.
- Many of these studies have measured locus of control using Rotter's scale which may not be accurate as it was designed to measure a different type of control to paranormal beliefs.
- Also evidence of the opposite - one study found a correlation between internal locus of control & belief in psi.
- Difference may be due in part to how paranormal beliefs are measured. Some researchers use core phonmena such as Australian Sheep-Goat scale whilst others use broader scales including UFO's, Superstitions etc.
- Tendency to have negative rather than positive emotions such as anger, anxiety & depression. Paranormal beliefs may create a distance from reality which act as a defence mechanism to reduce negative emotion. Seems the case that paranormal belief is associated with high levels of anxiety as a number of questionnaire studies have found these to be positively correlated. Strength of correlation is small & hasn't always been found.
- Williams et al:
- Method- 279 school children aged 13-16 completed 2 questionnaires using Eysenck's personality scale
- Results- Significant relationship between neuroticism & paranormal beliefs
- Evaluation- As the study involved Welsh school children results may not be generalised. Relied on self report so people may not have been honest.
- Having a creative personality has been linked to anomalous experience & beliefs. Creative person is one who is imaginative, creative, artistic & inventive. Thalbourne (2001) did a meta-analysis of 15 studies & found they all showed positive results. Those who had creative personality are more likely to believe paranormal activity is real. Gianotti et al (2001) asked ppts to think up words that would meaningfully connect 2 others and found that the more original words came from those with paranormal belief.
- May be because people who are creative are more likely to be open to different explanations of strange happenings.
- Most studies have been carried out on students so may lack generalisabilty.
Psychology of coincidence & probability judgements in anomalous experience
- Coincidence- When 2 events happen at about the same time so we assume they are linked.
- Probability judgement- assessing the likelihood that something will happen. Usually a subjective judgement & may differ from statistical probability. E.g. we think it's fate when we bump into someone from school on holiday but since you'd both have same school holidays & may have similar social backgrounds it isn't too unlikely.
- Some people are better at judging the probability of coincidences than others. If you underestimate probability you're more likely to believe events are not due to chance.
- Questions about probability: Shown by classic birthday problem. How many people would you need to have at a party to have a 50:50 chance that 2 of them share the same birthday? 23 this seems too low to most people. When Blackmore 1985 asked ppts questions about the birthday party paradox more non believers got this right than non believers.
- Repetition avoidances:
- Ppts were asked to produce a string of random numbers. Number of repetitions was counted. In a true series of random numbers there are likely to be repetitions but people who underestimate probability are less likely to repeat. Brugger et al found Sheep avoid repetition much more than goats.
- Conjunction mistakes: Rogers et al tested probability judgement by giving ppts 16 conjunction vignettes-descriptions where to events happen at the same time such as getting food poisoning after eating eggs. They were asked how likely it was for events to happen together. Sheep made more conjunction errors than goats.
- Blackmore says probability misjudgement although attractive does not have support. Published questionnaire in Daily Telegraph which asked people to complete ten statements to say if It was true for them & how true it might be for someone on the street. On average from over 6000 responses people said 2.4 of the statements were true for them & 3.6 would be true for others. Didn't support probability misjudgement as the predictions of believers & non believers were the same.
- General cognitive ability:
- Intelligence might be lower in believers & so they are less able to accurately judge. Backed up by some research. Research has found believers perform particularly badly on tests of syllogistic reasoning
- Some research has found the opposite. In a survey of New Scientist readers 67% said they thought ESP was an established fact or a likely possibility. Wiseman concluded that believers & non-believers differ not in cognitive ability generally but only in syllogistic reasoning.
- Thinking there is a link between 2 things when there isn't: Might be believers are more likely to see links between things than sceptics. Brugger et al found that people with more dopamine in their brain are more likely to find links. Ppts are shown real & scrambled faces & are shown made up words on a screen. Believers were more likely to see a face or a word when there wasn't one. When they were given a drug called L-Dopa to increase dopamine goats became more like sheep.
- Law of Truly large numbers:
- Many paranormal claims such as dream coming true are often rejected on the basis that this may have been a coincidence. LAw of truly large numbers. Given that every night billions of people dream it would be spooky if no one ever had a dream that seemed to come true. French estimated even if we take a conservative view that we should expect 3.6% of the population to have these sorts of views every year. Yet if this happens to us personally were unlikely to see it as a result of chance.
Explanations for Superstitious behaviour & Magical thinking
- Superstition is a belief not based on reality that one thing affects another. Can been seen in many areas of life such as theatre or sport.
- Magical thinking is believing that if you think something is going to happen or say it will happen it is more likely to. E.g. You might think thinking about winning the lottery is more likely to make it happen.
- Behaviourist Explanation
- Lack of Control & uncertainty
- Psychodynamic approach
Behaviourist explanation fro superstitious behaviour & Magical thinking
- Skinner thought superstitions developed through operant conditioning where an accidental association between 2 things are learnt.
- E.g. student uses particular pen in exam that goes well so she takes it to her next exam as her 'lucky pen'. Doing well with this pen is a coincidence but she thinks it's a cause of her good results.
- Skinner 1948 did an experiment where hungry pigeons were placed in a box & given a food pellet once every 15 seconds no matter what they did. After a few minutes the birds developed personal rituals such as walking around in circles & bobbing their heads up & down. It looked as if the pigeons thought their little routines were causing the release of the food even though there was no relationship between what they did & the food being released.
- Skinner explained this by saying that there had been an accidental pairing early on in the process with whatever the bird was doing & the release of the food.
- This explanation has been challenged. When study was repeated same rituals were seen but they were unconnected to the food giving-all the animals behaved in the same way. Rituals were produced just as often before the food was given & also occurred at other times so their explanation of accidental reinforcement seems unlikely.
- A Study with humans does support it. Ppts were subjected to uncontrollable noises in the library from their computer. They tried to press keys to stop it. IT stopped eventually but not because of what they did. Later it started again & they pressed the key they'd been pressing when it stopped-assuming they had caused it.
- Explanation only explains personal superstitions. There are also culturally transmitted ones for example Friday the 13th is unlucky in the Uk whereas in Greece Tuesday the 13th is lucky.
Lack of control & uncertainty for superstitious behaviour & magical thinking
- Research shows that superstitious thinking increases when there is more stress, uncertainty & lack of control. Claimed it satisfies the need for control & help to minimise the threat that it poses.
- In one experiment Dudley students increases their level of superstition after being given unsolvable puzzles to do. No such increase was found in a control group given solvable puzzles.
- Whitson et al also showed this in a study where they were asked to remember a situation that had happened in their lives. One group had to remember situations where they were in control & the other had to remember situations where they did not feel in control. Later they were all given stories involving superstitious behaviour e.g. stamping your foot three times before going into a meeting and asked to judge how much this affected what happened at the meeting. Those in the less control group were more likely to believe the superstitious behaviour affected what happened.
- They suggested that what happens is the feeling of control means you feel more confident to face up to unpredictable circumstances rather than withdraw from them.
Psychodynamic approach to superstitious behaviour & magical thinking
- Freaud saw magical thinking as a form of child-like thought where inner feelings are projected onto the outside world. E.g. a person might believe that if they think badly about a person that it might cause that persons death. He thought in adults it's a defence mechanism used as a way of coping with anxiety.
- AO2 Real world application: Donation rates for organs for transplants are very low this may be because of magical thinking. We link images of donation to our dead body. If we make people have a link between donation & something positive - giving someone else an extended life - we may get more donors.
Psychological research & explanations for psychic healing
- Psychic healing: Means any method to cure people of health problems by mental means. Can be face to face over the phone or from a distance. Methods include faith healing, prayer & laying on of hands (Therapeutic touch TT). In TT the therapist moves their hands over the patient's body to detect their 'aura' & aim to restore health by restoring energy field. Randi set out four criteria foe accepting psychic field:
- Disease must not be self terminating
- Recovery must be complete
- Recovery must take place in absence of any medical treatment
- must be medical opinion that the disease is not present after the healing
Explanations for success of psychic healing therapies
- Placebo effect
- Anxiety reduction
- Spontaneous remission
- Exaggeration or Fraud
Placebo effect in psychic healing
- Psychic healing very popular. When looking at evidence of success in terms of objective measurements there is little evidence of improvement. Suggests healing might be affected by the placebo effect. Generally recognised effect where a patient shows improvement after being given an inactive treatment such as a 'sugar' pill. Expectation of success influences healing rather than treatment itself.
- Patients have been found to respond to various kinds of placebo treatment, including sham surgery that only involve superficial cuts rather than genuine repair & acupuncture where needles are put in at incorrect acupuncture points. Estimated that 30-40% of positive recreation in drug trials may be the placebo effect.
- Modern tests of the effectiveness of healing now take this into account by using double blind tests in which patients are randomly allocated to a distant healing or a control condition and are not told which until afterwards.
Belief in psychic healing
- Many christian groups such as pentecostals believe in healing powers. Vicars may lay their hands on people or pray to heal. Belief seems to be important for success. Katra offers an explanation for this and says disbelief raises our psychic shield with result there can't be communication between healer & patient.
- Importance of belief can been seen in a study by Lyvers of the Australian psychic who tried on tele to cure people with back pain. No overall relief from pain was found but their was a correlation between total pain score & belief.
Anxiety reduction & psychic healing
Might be explained in terms of beneficial effects of contact with sympathetic person. Social support is known to reduce stress & enhance effectiveness of immune system.
Spontaneous remission & psychic healing
Randi's criteria would not rule out cases where there's been a misdiagnosis by doctors or cases of spontaneous remission. Regressions in cancer occur once is every 10000 cases - that is occasionally.
Exaggeration or fraud & psychic healing
Evidence for healing is often based on reports of individuals of their own experiences. Such reports have powerful influence & for some people are enough evidence. Such subjective accounts can be prone to exaggeration & bias. Although many psychic healer are sincere in their claims Randi has pointed out many known cases of fraud. Psychics in the Philippine use sleight of hand to create the impression they're operating on seriously ill patients without using surgical instruments. Also described case of American preacher Peter Popoff who claimed god was speaking to him directly given him details of medical condition of his congregation when in fact it was provided to him by his wife via radio receiver disguised as a hearing aid.
Research to support psychic healing
- Wirth 1990: In this study patients wounds were either treated with TT or no treatment. patients didn't know which condition they were in to reduce placebo effect Wirth found patients treated with TT healed faster. Research criticised. He failed to replicate own research on wound healing & researchers who wanted to discuss his research with him have been unable to contact him. Since then Wirth has been convicted for criminal fraud & given a 5 year prison sentence.
- Cha et al 2001: looked at effect of prayer on infertile women. Twice as many women who were prayed for by christian strangers became pregnant. Also been criticised. One of the authors withdrew his name afterwards saying he had nothing to do with the study. Cha has been accused of plagiarism in another journal.
- Krieger 2000: Thought healers increase vitality of patients. Took blood samples from patients before & after sessions to test them for haemoglobin levels. Healer placed one or both hands on patient where he went into a state of visualisation seeing positive energy around the patients body. 49 people treated control group of 29. Patients treated by healer had higher haemoglobin levels & generally felt better than control group. In follow up study year later haemoglobin levels still higher than controls.
Research not supporting psychic healing
- Rosa et al 1998: got 21 TT healers to sit on one side of a screen placing their hands through 2 holes in it. On other side of the screen experimenter placed one of her hands about 4 inches above the healer's right or left hand. TT healers should have been able to feel energy field on the hand but in fact their performance was not even as good as chance. Only correct 44% of the time. When study was repeated using ordinary people instead of TT healers with experimenter holding their hand only 3 inches away the results were better than chance may be because they were able to detect heat from experimenters hand. in another study that eliminated heat results were at chance level. TT supporters have criticised the Rosa et al study because it was designed by a 9 year old girl though this is not necessarily a problem & article was published in a reputable American journal. Supporters have also said it's invalid because experimenter was not ill which might have affected their aura.
- Lyvers et al 2006: wanted to test powers of well known psychic on Australian TV. Recruited 20 volunteers who suffered back pain. Healer thought of psychic ability as a gift & did not accept any money. During experiment all the pp were told the psychic was focusing on them in fact he only focused on the treatment group. No overall reduction in pain was found by either group. There was a correlation between belief & final pain score. All pp filled in a questionnaire before treatment & this correlated positively with the extent to which pain was reduced. Suggests belief plays central roll in psychic healing.
Psychic mediums claim to be able to communicate with people in the afterlife or spirit world
Explanations for psychic mediumship
- Cold Reading
- Barnum Effect Fishing
- Conjurors can do the things mediums do
- Mediumship Fraud
Cold reading in Mediumship
Members of public are often according to surveys impressed with encounters with psychic readers or mediums. Survey in 1985 found that 83% had found experience useful. Difficult to explain why Members of the public come away so impressed when results from controlled tests have been generally disappointing. Success has often been explained by the use of common channels of communication called 'Cold reading'. When reader is able to persuade a client he has never met before he knows all about his personality & problems. Reader uses many cues such as shrewd observation non verbal & verbal feedback to create this illusion. Even without seeing the person they can pick upinfo from the tone of voice & the response to previous statement.
Barnum effect in psychic mediumship
Cold reader often starts with some general statements about the person such as 'I see the letter J' or 'I see a recent loss of life' & the responses can be used later in the conversation. Barnum effect is tendency of people to accept vague or general statements to describe their personality even though they apply to virtually everyone. 'Im seeing the month of January here' Client is left to fill in gaps.
Fishing in psychic mediumship
General questions give reader some material to begin but they also pick up on info during the interaction. Other data will be teased out through 'Fishing' when client unknowingly reveals things about themselves. E.g if they ask question about health 'I get the impression someone close to you has been ill recently' The client only needs to mention a spouse or son or daughter for reader to know he can safely talk about family matters & events.
Suggestibility in mediumship
Many people who go to Mediums do so for a particular reason so are particularly vulnerable & open to suggestion at this time. Famous medium John Edward criticised for targeting these people. Interesting messages sent back from grave are usually positive- X is doing well Y is happy. Life after death always seems to be positive which is perhaps surprising & could indicate people are being told what they want to hear rather than actual messages.
Conjurors can do the same things mediums do
Magicians can fake all the things mediums do such as going into a trance & levitating objects. This does not necessarily rule out genuine mediumship.
Many incidences of mediums being frauds. E.g it was birth of spiritualism in 1848 that began modern interest in mediumship. Started by 2 young sisters Kate & Margaret Fox who reported hearing strange rapping noises. However Margaret admitted 40 years later noises were fake-made mainly by her cracking her toe & ankle joints. Had begun as a prank and got out of hand & sisters had felt unable to own up.
Research supporting mediumship
- Scole report:
- Between 1993 & 1998 Keen et al described the results of over 500 experiments at Scole in Norfolk. Researches witnessed 37 seances in rooms that were thoroughly searched beforehand to prevent trickery. Professional magician also present to identify any attempts at fraud. During these seances a number of paranormal occurrences were reported. These included the materialisation of objects, levitation, patterns of light, voices & the appearance of whole people or body parts. Experiment heavily criticised & isn't widely accepted as evidence. Experimental conditions unreliable-they were controlled by the mediums. E.g Researches wanted to use infra-red imaging as most seances done in the dark but mediums claimed it would distract them. Also experimenters believed in the paranormal so there may have been experimenter effects.
- Schwartz 2007:
- Conducted a triple blind technique with 8 uni students who had experienced loss of someone close & 8 mediums who had independently shown a high degree of accuracy in their reading. Results showed certain mediums could give accurate info about the deceased. Beischel & Schwartz suggested other influences that could explain this were the survival of consciousness or super psi (skills such as strong ESP)
- Russek & Schwartz 2001
- Found highly skilled mediums can give accurate readings of people they know nothing about, revealing info that is so personal that the chances of guessing the details is well below the level of chance
Research no supporting psychic mediums
- Wiseman 2003
- conducted false seance even though ppts knew it was fake they seemed to be taken in by the events.
- Wiseman et al 2005
- Arranged for 5 mediums to give a reading for 5 people. Each person read all 25 readings produced & rated them on how relevant they were to themselves. Rating was lowest for statements that had been specifically written for them.
Summary for psychic mediumship
While scientific research suggests a well trained psychic does have some abilities such research has its flaws. It is a difficult area to research objectively & it's become clear many claiming to have psychic powers are fraudsters. Currently little research in this field & much more is needed before any firm conclusions can be made.
Out of body experiences (OBE)
Sensation of being able to see yourself & the world by floating outside of your body. Around 7% of people claim to have an 'astral cord' which links the OBE to the physical body to help it return. Spontaneous & rare events so studying them is difficult. Most evidence based on case studies. About 15-20% of people have experienced an OBE.
Explanations of OBE's
- MAy be due to biological factors
- Visual disruption
- Personality & Belief
Biological factors explanation of OBE's
- OBE's seem to occur more frequently in people with migraines or epilepsy.
- Brain damaged people who have OBE's have damage to the temporal & partial regions of the brain which is interesting as these are the areas in the brain thought to be responsible for self perception.
- Blanke et al 2002 Accidentally induced OBE's by electrically stimulating a part of the brain (TPJ) in a women with epilepsy. Led to them studying normal subjects as well. Suggests explanations might be some sort of brain malfunction.
- Difficult to study OBE's as they are unpredictable & if researcher was there the experience would stop as soon as the person reported it. Therefore most research conducted on artificially induced OBE's Some don't regard these as the same thing as those naturally occurring.
- Early studies of biological activity while having an OBE did not find any difference in sleep patterns, except subjects were in very relaxed awake state & definitely not dreaming.
Visual disruption explanation for OBE's
- Ehrsson is sceptical about the nature of OBE's & has searched for a way to study them. Stimulation studies have been able to recreate a feeling of disembodiment by scrambling a persons visual & touch sensations
- Ehrsson 2007
- 42 ppts stood in front of a camera wearing video-display goggles. They could see their own back & a virtual body of themselves standing in front of them. Created an illusion where people felt they were outside their physical bodies & looking at their bodies from this perspective. When pen was used to stroke their back they reported it was like pen was being stroked on virtual body.
- Ehrsson concluded visual disruption can lead to the experience of a new viewpoint that might explain OBE experiences.
- Sample was small & volunteer sample used so may not be representative of target population. Demand characteristics meant ppts didn't know much about the aims of the investigation so informed consent unlikely. Means OBE's can be studies in labs.
Personality & beliefs in explaining OBE's
- Although many biologists produce convincing arguments that biological factors cause OBE's belief must also be a factor. OBE's reported more often by people with paranormal beliefs.
- Gow et al 2004 in a study of 'believers' and 'non believers' asked 167 ppts to complete a series of questionnaires. Those that had had out of body experiences were more fantasy prone, scored higher on hypnotisability & on dissociation (ability to seperate different aspects of conscious activity) and were more likely to believe in the paranormal. Not evidence people with OBE's are mentally ill. Also we don't know what cause is & what is effect. it is haard to seperate these.
Near death experiences NDE's
- NDE's are individual experiences that people sometime report after a near death experience. This is when a person is close to death or is pronounced dead but recovers. Estimates say that as many as 20% of heart attack survivors report them.
- Common features include:
- Intense emotion
- Movement through darkness towards light
- Meeting with dead loved ones
- A life review
- For some a decision to return to their bodies
- Seeing your body from above
Explanations of NDE's
- REM intrusions
- LAck of oxygen
- Drugs given
- Possibility of life after death
Endorphins explanations of NDE's
- One explanation is endorphines (bodies natural pain killers) are released at time of pain or stress which can lead to feelings of euphoris & detachment.
- Research based on that carried out by Carr 1982. Endorphins are crucial in blocking out pain & are known to give people a sense of well being.
- NDE's increasingly common endorphins account can't explain this
- Other research suggests it's not level of endorphins but the neurotransmitter serotonin that's more important. It's also argues endorphins don't give hallucinogenic effect needed it is a much more complicated process.
- Another suggestion is that NDE's are due to REM intrusions which create hallucinations. REM sleep is associated with dreaming. A REM intrusion occurs when brain is awake but flips into REM state resulting in a mixed state that could disrupt sensory information.
- Nelson et al 2006 studied 55 ppts who had experienced NDE's & 55 controls. He found NDE group also more likely to suffer from REM intrusions when the brain flips into REM state.
Lack of oxygen explanation in NDE's
- Some symptoms may come about as the brain reacts to a lack of oxygen
- Whinnery 1997 found that fighter pilots can sometimes lose consciousness for brief periods when their bodies are subjected to massive G forces that reduce blood flow to the head. Reported similar NDE experiences including the tunnel & light though these experiences ten to be more fragmented & confused than typical NDE's
- Can't explain people who have NDE without lack of oxygen
- Eye has most visual cells in the centre of the visual field. If cells are triggered randomly as happens with lack of oxygen this will produce the effect of a bright light in the centre of the visual field & a gradual darkening at the edge i.e a tunnel
- Sabom 1998 studied body gases in people who have had NDE's including oxygen & found normal gas levels. Not all researchers are convinced his chosen method of taking gases from blood samples is accurate.
Drugs given explanation of NDE's
- Given the high doses of drugs given during operations some scientists have suggested that NDE's are a by-product of the drugs given.
- Found possible to create NDE's using drug Ketamine. However some patients that have had NDE have not been under the influence of drugs. Greyson et al 1980 also found that patients who have taken painkillers are less likely to report an NDE & if they do it's less vivid.
Expectation's explanation for NDE's
- According to research culture & religion affect the content & form of the NDE. E.g. Christians talk about their being a jesus form in the light whereas Hindus see Hindu figures. Suggests expectation plays a part.
- Can't account for similarities of NDE's across cultures
- Also someone attempting suicide does not necessarily have a horrible NDE, it's often similar to others & NDE can reduce further suicide attempts
Possibility of life after death in explaining NDE's
- Blackmore argues that brain & body explanations can't explain the belief that a 'soul' leaves the body, which is common in both Western & non-Western cultures.
- No scientific way of finding out if this is true
- Evidence tends to come from qualitative reports from case studies where patients have been able to report hearing conversations or seeing things they should not have been able to see.
- Clark 1994 reports the case of 'Maris' who during her NDE saw a shoe on a high ledge in hospital. Later her social worker checked & found the shoe. Trouble is there is not an independent account of this so it is a story & not a scientific account. While supporters say this is conclusive evidence, sceptics say there is no scientific basis to the claims.
The Scientific method
- Peer review: Fellow scientist evaluate research & assess whether it should be published or not
- Objective: Findings should not be influenced by the person that did the research. Should be on evidence that's measurable & unbiased.
- Observable: Based on the examination & measurement on the behaviors that are visible for us all to see.
- Testable: open to direct assessment & measurement.
- Empirical: Based on experiments, experience or observation not beliefs or intuition.
- Replicable: Others should be able to repeat the research & get the same results.
Scientific method progresses by hypothesis testing. We want to find something out and so form a hypothesis that can be tested in research. We must now try & do everything we can to disprove it.
Popper's Scientific process
Popper 1959 said the scientific process follows a logical process from finding a gap in the knowledge to eventually developing a theory:Identify a problem & make an aimDevelop a clear & testable hypothesisChose the method to test the hypothesisAnalyse the results & draw conclusionsRepeat the study in a different situation Form new laws & theories about human behaviour.A good theory is one that can be empirically tested, it has to be falsifiable rather than looking for evidence for a theory a researcher should look for ways to disprove it. If a researcher tries to disprove a theory & cannot it is strengthened. If shown to be wrong it's either modified or replaced.
Kuhn Scientific process
Kuhn disagreed with Popper. He through scientific knowledge developed through revolutions. Thought one theory is dominant despite of odd changes. Gradually evidence builds up against it until it can't be maintained. Then overthrown & replaced. Kuhn didn't use the term theory but spoke of a paradigm- A shared sat of assumptions about the subject.
New Paradigm research
- Towards the end of the 20th century psychologist started to question the use of the traditional scientific approach to psychology. Research tends to study people in unnatural conditions such a labs or other uni building. Scientific approach emphasises control & treats people as passive ppts. People aren't asked how they think or feel which make the approach superficial.
- As a result alternatives to the scientific approach have been suggested by a number of group including postmodernists & feminists. This has been called 'New paradigm research' & tries to understand the subjective world of the ppt, recognising that more complex data can not be reduced easily to numbers. Such info comes from in-depth interviews, written material such as diaries or blogs. Focuses on the underlying meanings values & emotion of the info & attempts to understand the experiences & cultural world of the ppt. Ppts are viewed as active collaborators rather than passive ppts obeying instructions. Research is qualitative rather than quantitive.
- New paradigm approach has a growing following in psychology but does not mean that conventional scientific approach in psychology is being replaced. Psychologists use conventional & new paradigms when appropriate.
Process of Peer Review
- Evaluation of scientific work by other experts who are in the same field. Ensures the research carried out & is published is of high quality.
- Generally unpaid. Number of reviewers for each piece. When a psychologist has research they want published they prepare a manuscript & send it to a journal. The editor sends copies to other psychologists that are experts in that topic. They are the peer reviewers. Carefully read & assess all aspects of it. Then send it back to editor with comments & a recommendation about whether or not it should be published. Editor reads these & decides whether the research is published, revised or rejected.
Purpose of peer review
- Research funding: Research paid for by government & charities. They need reviews to decide which research will be worthwhile.
- Publication in scientific journals: Way of stopping faulty data being given to the public. Before that research was simply published & it was up to opponents to disprove it.
- Rating university departments: All science departments in Uni's are expected to conduct research. Future funding will depend on good ratings from peer review.
Problems with Peer review
- Richard Smith says it is slow, expensive,higly subjective, prone to bias & almost useless at detecting fraud.
- Not always possible to find an expert: Means poor research may be passed because reviewer didn't really understand it.
- Anonymity/Bias: done so reviewers can be honest & objective but could have opposite effect & be an opportunity to settle old scores or bury rival research. Reviewers tend to be especially critical of those conclusion that contradict their own views.
- File drawer phenomena: Research findings show negative findings don't tend to get published as much as those with support.
- Self report Techniques
- Case Study
- Content analysis
- Can give cause & effect
- All-IV manipulated while all other variables are kept constant
- Lab-In a controlled room
- Field-In A natural setting
- Natural-Someone else manipulates IV and expt goes in after to see effects.
- One advantage: Lab-High degree of control which means researchers can be certain the IV is causing results rather than extraneous variables. So results more valid & replicable.
- One Disadvantage: Lab- The high degree of control can make the experiment unlike real life (lack ecological validity)
- Systematically watching & recording behaviour. Behavioural categories (e.g. kick/hit/shout) that are ticked in a tally chart.
- Naturalistic-In a natural setting
- Needs inter-rater reliability between observers
- Ethics-Only in public places/no consent given/privacy.
- Time sampling- look every x minutes
- Event sampling have check list
- One advantage: High realism. Since it takes part in natural setting & people don't know they're being observed they are more likely to behave naturally. Gives results higher ecological validity & means they can be generalised to others.
- One disadvantage: Lack of control. Since it takes place in natural setting it is difficult to control extraneous variable which may affect results. Makes it impossible to establish cause & effect & means replication is difficult.
- Shows a relationship between 2 variables
- Correlation coefficient -1 to +1
- Only shown on scatter graph
- One advantage: Gives a precise measure of the strength of relationship e.g. a correlation co-efficient of -0.8 would be a strong negative relationship.
- One disadvantage: Can't show cause & effect it can only establish a relationship between 2 things.
Self report techniques
- Open/Closed questions
- One advantage: Although they take long to write out once this is done it is easy to send them or email them out to ppts. Means a large sample can be asked & results can be generalised to the target population
- One disadvantage: Poor returns. Questionnaires/surveys often have low rates of return or certain questions are missed off. Also people may only answer if interested in the topic. Difficult to generalise results to target population.
- Structured/unstructured/semi structured
- One advantage: Particularly useful for sensitive topics because trust can be built up. Unlike postal survey where people may just not reply.
- One disadvantage: Interviewer bias may mean it's difficult to remain unbiased when asking questions or interpreting results, especially when qualitative data is gained. Makes results less reliable.
- Detailed study of one person or event
- One advantage: Richer in depth detailed information can be provided than in some methods such as lab expts. Make results more reliable
- One disadvantage: Difficult to generalise to target population as only one person is studied. Reason they are studied is often because they are unusual &unlike the rest of the target population.
- Analysis of content of something e.g. diary or advert on tele.
- Like an observation but of objects people produce rather than the people themselves.
- Look at categories
- One advantage: High ecological validity because based on what people actually do & real documents. Means results more valid & can be generalised to target population.
- One disadvantage: Observer bias means the different observers may interpret the meaning of the categories differently. Means results can lack objectivity & be less valid.
Design of experiment
- Independent groups
- Repeated measures
- Matched pairs
- Different people used in each condition
- One advantage: No order effects as everybody does the study at the same time. Means people don't get better from practice or worse from being tired or bored.
- One disadvantage: Differences between individuals in the groups may affect the results.
- How to overcome problems: Randomly put people in groups rather than letting them choose. Less likely to pick something they find easier or go with friends who may be similar.
- Same people used in both conditions
- One advantage: Can control differences in groups. Means differences in age/height/IQ ect are not affected
- One disadvantage: Order effects. People may get better or worse as they've done study before from practice or boredom
- How to overcome problems: Counterbalancing. Some people start in first condition some people start in the second condition rather than all starting in the same place. Called ABBA design.
- ppts are matched on key characteristics e.g. age/IQ ect.
- One advantage: No order effects
- One disadvantage: Can take a long time & be very difficult to match ppts on key variables. Large sample is needed to choose from. For this reason it's used less often than other methods
- How to overcome problems: Use identical twins as they are already matched on key criteria.
- Key issue with sampling is whether the results can be generalised to the rest of the target population. Much psychological research uses opportunity & volunteer samples. In a study in 2000 researchers found 71% of ppts were Uni students.
- Ask anyone who's around & willing to take part.
- One advantage: Easy to do. Most people in psychological research are psychology students as Uni as they are easily available & cheap to use.
- One disadvantage: Doesn't represent tp. Because they are often students they may be a certain age, class & intelligence level. Difficult to generalise to tp.
- Everybody in the tp has an equal opportunity of being chosen.
- Put al names of tp in a hat & pick out number needed.
- One advantage: Likely to give representative sample more than any other sample method. Makes results more valid as they can be generalised to tp.
- One disadvantage: Only works in tp is small. If tp was all under 5's in Nottingham it's be very time consuming & expensive to get everyones names to use.
- Stick up advert on notice board or put in newspaper & ask for volunteers on a particular topic.
- One advantage: May be able to get people who would be difficult to find using other methods e.g. people who have had a miscarriage
- One disadvantage: May only get certain types volunteering e.g. people with more time may not be typical of tp so results may not be generalised.
A prediction about what will happen in a study
Says the results are due to chance not the IV
The thing you manipulate or change in an experiment whilst everything else is kept constant.
The thing you measure in an experiment
Predicts the direction the results will go in. Is used when previous results have shown what they are likely to be.
Non directional hypothesis
Does not say how results are likely to go. Used when there's no previous result on the subject.
Types of experiment
- Lab- HAs IV manipulated in controlled room. (more control/less ecological validity)
- Field-Has IV manipulated but done in a natural setting (Less control/higher realism/difficult to replicate)
- Natural-IV manipulated by somebody else & researcher come in afterwards to measure DV (Hard to replicate/Higher ecological validity)
Ways to control variables
SIngle blind/Double blind/ Standardised procedures/Standardised instructions
- Ways the researcher affects results
- By wanting results to go in certain direction so may smile & frown unconsciously
- Personal qualities such as gender,voice,clothing etc which may affect ppts.
Things about the experiment that give cues to ppts to act in certain ways.
Social desirability bias
Participants may lie to try & look good.
Small scale versions of the real thing done by a few ppts of the tp. Try to iron out any problems before the real thing & so save money. Make sure researchers are familiar with procedure & timing. Particularly useful for questionnaires to check questions aren't ambiguous.
Reliability & consistency
Reliability mean consistency- a test or observer is reliable if they produce the same results every time. Instruments like rulers & stopwatches are very reliable; doesn't matter who uses them they give the same answer.
Types of reliabilty
- External reliability: measuring if same results are achieved in a situation every time. E.g. if you interview person on one day & then week later using same questions results should be the same or the interview is not reliable.
- Internal reliability: Measures whether something is consistent within itself. E.g all questions on an IQ test should measure the same thing.
- Inter-rater reliability: In an observation looks at whether the two observers are recording the same thing. Checked by doing a correlation or using video or audio tapes.
Ways of testing external reliability
Test-Retest: Give the test twice to the same group of people. A correlation between their scores is calculated. Second test must be taken after a period of time so that ppts do not simply recall what they did last time.
Ways of testing internal reliabilty
Split-half method: Compare performance on 2 halves of the questionnaire/ test. Test can be split in several ways e.g first half & second half, odd number & even number questions or randomly. If test is reliable halves should give the same score.
Was of testing inter rater reliabilty
Correlation. Here it is important that the observers are recording the same thing. Checked by using a correlation analysis or using videotapes or audiotapes.
Ways to improve reliabilty
- All observers should be trained throughly in the techniques they are to use
- All key terms should be operationalised & understood fully. e.g. if studying aggressiveness of children you would need to understand exactly what would be categorized as aggressive.
- Pilot studies should be used to check everything works before carrying out the investigation.
External validity shows the extent to which research can be generalised to other situations & other people. Often a problem is if the sample is not representative.
Whether the test measures what it is supposed to measure. e.g. measuring circumference of head is not a valid way of measuring intelligence.
Ways of measuring validity
- Face validity: Most basic way of assessing validity & refers to if the test looks right & if it measures what it is supposed to measure.
- Concurrent validity: Can be checked by comparing the test with another that's already established. Ppts take 2 tests & the scores are compared.
Ways to improve validity
- Reduce demand characteristics & participant reactivity. Can be done by single blind & double blind procedure.
- Standardised instructions & Standardised procedure.
- Confidentiality & anonymity: ppts have the right to expect that all data obtained during the research will remain confidential. Number should be given instead of names immediately & should be used throughout. If research is published data should be anonymous & should be presented in a way so that an individuals answer can't be identified.
- Deception: Should only be used as a last resort when there's no alternative. Ppts should feel the deception was worthwhile when debriefed. Using deception means informed consent can't be obtained. In this case general consent can be obtained or presumptive consent.
- Right to withdraw: Ppts have the right to withdraw at any time during the study & should be told this at the start.
- Protection of ppts: Psychologists have a responsibility to protect their ppts from any mental or physical harm. risk should not be more than that to which they are exposed to in everyday life.
- Debriefing: Following a study ppts should be fully informed about the nature of the study. Experiences should be discussed. Debriefing does not justify unethical procedures.
- Observational research: Ppts should not be observed in situations where they would not normally expect to be observed.
What can we do to make sure ethical guidlines are met?
- Ethical committees: Most research given funding only after being passed by an ethical committee who will weigh up risks & potential benefits of the research. If psychologist break ethical guidelines they would be able to bar them from the psychological society & this would prevent them from doing any further research/promotion etc.
- Informed consent: If it is not possible to gain informed consent- because study is using deception- then a full debriefing is necessary where ppts are told the true purpose of the study. They should feel happy that deception was worthwhile.
- Confidentiality: Ppts must be informed that all results are confidential. Usually in the letter of consent. Referred to by number not name.
- Right to withdraw: Not only do ppts have the right to withdraw- but they must be aware they have the right to withdraw at any time during the study even afterwards. Usually made clear in letter of consent.
- tables summarising results
- Pictorial representations such as histogrmas, bar charts & frequency polygons
- Measures of central tendency such as mean/mode/median
- Measure of dispersion such as range & standard deviation
- Measures of relationships or correlations between variables.
Tables can be used to summarise Quantitative data
- Tables can be used to clearly present the data & show any patterns in the scores
- Tables of 'raw' data show the scores before any analysis has been done on them
- Other tables may shoe descriptive statistics such as mean, rang & standardised deviation.
Bar charts can be used for Non-continuous data
- Bar charts are usually used to present non continuous data- when a variable falls into categories rather than being measured on a numbered scale.
- Note columns in bar charts don't touch each other. Also it's preferable to always show the full vertical scale or clearly indicate when it isn't all shown.
Histograms are for continuous data
- Histograms show data measured on a continuous scale of measurement.
- Each column shows a class interval and the columns touch each other
- All intervals are shown even if there are no scores within them.
- Height of the column shows the number of values in that interval.
Scattergraphs show relationships between co variables
- Correlation is a measure of the relationship between 2 variables. Correlation coefficient is produced range from -1 to +1. In a correlation study data can be displayed in scattergraphs.
- Positive correlation: as one variable rises so does the other & vice versa
- Negative correlation: As one variable rises other one falls and vice versa
- No correlation: IF correlation is 0 or close to 0 then 2 variables aren't linked.
MEasures of central tendency
- Mean: Sum of scores divided by number of scores.
- Advantage: useful because it takes into account all the scores
- Disadvantage: Can be skewed by 1 or 2 extreme scores
- Median: Data is put in order & median is the middle value. If even number median if half way between 2 middle scores.
- Advantage: Not affected by extreme scores
- Disadvantage: Not as sensitive as mean as not all scores are taken into consideration.
- Mode: Most frequently occurring score.
- Advantage: Only method that can be used with nominal data
- Disadvantage: Can be several modes in a set of data making it unusable.
Measure of dispersion
- Range: Calculated by taking lowest value away from the highest.
- Advantage: Easier to work out than standard deviation means less mistakes will be made & results will be more reliable.
- Disadvantages: It can be distorted by extreme scores. Means results might be unreliable.
- Standard deviation:
- Measure of the spread of a set of scores from the mean.
- Advantage: Give more detailed info than the range. Means you can get more info from the data collected.
- Disadvantage: More difficult to work out than the range. Means errors more likely to be made which would make the result unreliable. Also takes longer to work out.
Probability & Significance
In science to establish laws we need to look at the probability or certainty that results didn't occur by chance. Probability is a numerical measure of how likely something is to have occurred by chance. With 0 being % and 1 being 100%. the closer to 0% the findings of the research are the greater the confidence the researcher has in saying they were due to IV & can reject the null hypothesis. P <0.05 means the probability of our result being due to chance is less than or equal to 0.05 or 5/100 which is the same as 5%
How do we decided on the critical value
- 0.1% level (p<0.001)-Very highly significant
- 1% level (p<0.01) Highly significant
- 5% level (p<0.05) Significant
- It depends how important research is
- 1% in research affecting human health we want to take few if any chances
- 5% generally used in psychological research
- 10% rather thin, but worth reporting because follow up studies might prove worthwhile.
Type one & type two errors
- If we have a 1% level (Too low/too stringent) we run the risk of accepting a null hypothesis which is true=type 2 erroe
- If we have 10% level (too high/too easy) we may reject a null hypothesis which is true=type 1 error
- Therefor 5% level is just right for most psychology research and is most commonly used as it reduces the risk of making a type 1 error (too lenient) or type 2 error (too strict)
- Different tests are used for different designs
- There are 4 tests:
- Spearman's Rho- Used for correlation
- Chi-Squared- Used with nominal data
- Mann Whitney U- Used with independent groups
- Wilcoxon T-USed with repeated measure (or matched pairs)
- When we use a test the data is analysed to calculate an observed value. In each test the observed value has a different name.
- Spearman's Rho-Correlation coefficient
- Chi squared-x2Mann Whitney U- U
- Wilcoxon T-T
- To find this we have to compare the observed value that we have calculated with the tabled or critical value.
- In order to do this we need to know
- N-Number of participants
- What the level of significance is (p-usually 5%)
- If the hypothesis is directional or non directional
- For Chi squared test the degrees of freedom (df). Calculated by number of rows -1 times by number of columns -1.
Many tests except Chi Squared need data to be ranked. This involves giving a number to each score. Usually done with lowest score being given rank 1 the next 2 and so on. If two scores share the same rank they are both given the middle rank.
Levels of data measurement
- Named categories
- Data is separate categories. You just record the number in each category
- Ordered, ranked
- Data is ordered in some way, difference between each person does not have to be the same. Often used for subjective measurements in psychology such as IQ/attractiveness/pleasantness.
Intervals are the exact size. data id measured using units of equal intervals such as when measure time,speed,weight & height
Other things that affect choice of inferential test
- Direction or non directional
- Test of similarity or difference
- Significance level
- Degree of freedom
- For a correlation
- Test is used because data is ordinal & is a correlation study.
- If the observed value is equal to or greater than the critical value the the hypothesis is accepted & the null rejected. The sign - or + is not important but tells you if the correlation is negative or positive.
- If observed value is greater then critical value we'd normally accept the hypothesis & reject the null but if the observed value sign is in the opposite direction to what was predicted you must accept the null.
- Used when hypothesis predicts a difference between two condition or an association between two co variables. An independent groups design is used, so ppts will only have one sat of data. Data nominal will be in frequency/categories & not be in percentages.
- To find critical value you need to know if the hypothesis is one tailed or two tailed, What the level of significance is & the degrees of freedom-Df=(number of rows-1)x(number of columns-1)
- If observed value is greater or equal to the critical value then the null hypothesis can be rejected.
Mann Whtney U test
- Test of difference which is suitbale for independent data. Each condition tested separately.
- Research is looking to find if there's a difference between 2 sample of data. Generally used for experiments
- When hypothesis predicts they'll be a difference between 2 groups
- Can be used when ordinal or interval/ratio data is converted into ordinal data.
- N1=Number of value in the smaller sample
- N2=Number of values in the larger sample
- For critical value you'll need to know:
- What N1 & N2 are
- Whether it's direction or non directional
- What your probability level is
- If observed value is equal to or less than the critical value the null hypothesis is rejected.
- Used when it's a test of difference when 2 sets of data are related & therefore is a repeated measures design.
- Ppts will be tested in both conditions & then scores are compared to see if there's any difference between the two.
- When hypothesis predicts they'll be a difference between 2 conditions
- Used for ordinal data or interval/ratio data that's converted into ordinal data
- For critical value you'll need to know the number of pairs. Anyone with difference score of 0 is not included
- Whether hypothesis is directional or not
- Level of significance
- If observed value is less than to or equal than critical value the null hypothesis is rejected.
Conventions for reporting psychological investigation
- Method (standardised procedure)
- Consent form
- Qualitative data
Summary of the study covering aims/hypothesis, method/procedures, results & conclusions
What the researcher intends to investigate. Often includes a review of all previous research explaining why the researcher plans to conduct this particular study. Researcher will state hypothesis & null hypothesis.
Method (standardised procedure)
- Detailed description of what the researchers did, providing enough information for the study to be replicated. It includes:
- Apparatus used
- Exact procedure
- Any instruction given before (the brief) and after (the debrief)
- Descriptive statistics including tables, graphs, measure of central tendency, measure of dispersion.
- Inferential statistics include test used, probability level, observed value & critical value. All calculations & raw data would go in the appendix at the back of the research.
- Researcher will discuss results offering explanations for results
- They would discuss any problems with the research & how it could be put right
- They would discuss implications of the research & any ideas for future research.
- Full details of any journals, articles or books that are mentioned.
- Should be in alphabetical order.
At the back of the report the appendix contains additional pieces of information such as the consent form, any diagrams of apparatus, statistical calculations, raw data etc.
Should contain all the details for a participant to make an informed decision about whether or not to take part. What it involves, how long it will take, any possible risks etc. Might say they have right to withdraw at any time. Might also inform ppts their data is confidential.
- Although similar in some ways there are no specific hypotheses but aims for the research.
- Design section of the method is not relevant and as no numbers are used neither descriptive or inferential statistics are included in the results. Instead typically they'll be a report on analytic theme using supportive quotations.
Analysis of Qualitative data
- Qualitative research uses smaller samples than quantitative research but usually involves the collection of a large amount of data. There are no agreed ways to analyse qualitative data. Each researcher has their own ideas for the best way to do it.
- Gathering & recording data
- Categories (sometimes coding units)
- Using quotations
- Turning it into quantitative data
- Involving the participant
Gathering & recording data
Data is gathered using non experimental methods which includes naturalistic observation, interview, questionnaire & case study. Data needs to be recorded thoroughly.
- Coding is the process of identifying categories, themes, phrases or key words that may be found in any set of data. Coding is not a superficial categorisation but a thoughtful process aimed at trying to understand the meaning of the data.
- First step is often to put data into categories or coding units.
- Sometimes categories suggested by the ppts will be used to avoid researcher bias.
- Analysis of qualitative data needs repeated reviewing of the data in order to consider further categories & to reassess meaning.
Examples of behaviour with the category can be represented using quotes from ppts or descriptions of typical behaviours within that category.
Turning it into quantitative data
Frequency of occurrences in each category may be counted thus qualitative data is turned into quantitative data.
Involving the participant
Another technique to make sure the appropriate detail is preserved is to involve the ppt. In a case study the ppt may read the researcher report of their findings & comment on whether it fairly reflects their feelings & experiences. This is called collaborative research.
This is where results are compared from different studies of the same person or thing. Technique is used to show the qualitative research has validity.
The analysis of the content of something. a researcher may study the gender content of magazine advertisements. Content analysis is a form of indirect observation because you are not observing people directly but through the artefacts they produce. These artefacts can be TV programmes, books, songs, paintings etc.
Advantages of content analysis
- Has high ecological validity because they are based on direct observations of what people actually do and real communications, such as recent newspapers & children's books.
- When resources can be kept or accessed findings can be replicated & so tested for reliability.
Disadvantages of content analysis
- Observer bias reduces the objectivity & validity of the findings because observers may interpret the meaning of the behavioural categories differently.
- Likely to be culture-bias because the interpretation of verbal or written content will be affected by the language & culture of the observer & behavioural categories used.
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