Females' growth spurts occur an average of ____ years earlier than males' growth spurts.
At what age range do females growth spurt range?
Females: 8 or 9 to 14
Males: 10 to 16
Because of the different growth spurt ranges between males and females, for a brief time between the agers of 10 and 14 _________
girls are larger than boys
In the prenatal period the head comprises a large proportion of total body lenth (_____) due to _____.
1/2 to 1/4
early brain growth
The trend of the head comprising a large proportion of total body lenth dimishes with age until ______, when the head comprises about ____ of the total body size.
Body fat increases at the end of the ______ stage and continues to increase after birth, reaching a peak at about _____.
Baby's body fat helps the baby maintain _____.
Babies begin to slim down in the _____ year of life and continue to do so into middle childhood.
Starting at about age ____, girls add body fat while males continue to lose body fat.
Muscle gradually accumulates throughout childhood and dramatically increases during ____.
While both sexes gain muscle during puberty, boys gain _____% more than girls.
The fact that boys gian 150% more muscle during puberty than girls likely contributes to boys' greater _____ during adolescence.
Explosion in Motor Skills during preschool and middle childhood is caused by:
changing proportions (balance)
Motor skills are gradually acquired as children gorw, and these skills become better developed according to their:
increased size and strength
interests and goals
Chldren spend less time in informal, outdoor play than in previous generations due to:
Meanwhile, organized have drastically expanded. ____% of North American children (____% of boys and _____% of girls) participate in organzed sports at some point between ages 5 and 14.
Reseach indicates that as long as parents and coaches emphasize effort, improvement, and teamwork, participation is related to:
enjoyment of sports
When competition is over-emphasized and coaches or parents exert too much pressure on children to perform well, the results include:
sex differences in motor development in preschool:
Boys are slightly stronger than girls
Sex differences in motor development at age 5
boys can jump slightly farther, throw 5' farther and run slightly faster
Sex differences in motor development at age 12
boys can throw 43' farther and are better at kicking, batting, catching, and dribbling
Sex differences in motor development at age 12
Girls are better in fine motor skills (handwriting), balance, and agility (e.g. hopping, skipping)
_______ appears to be responsible for the increasing sex differences in motor skills
Sex differences in motor skills are _____ in early childhood, and encouragement of different activities for boys and girls leads to _ of those differences.
In _____, the federal government required schools to provide equal opportunities for males and females in all areas, including ____.
the federal goverment requiring schools to provide equal opportunities for males and females in athletics has increased girls' participation in sports, but there is still a gender gap in high school sports participation (____% vs. ____%)
Physcial activity _____ with age for both sexes, partly due to cutbacks in physical education programs in high school.
only ____% of American high school students take any physical education, and only _____% do so every day.
the only hormone produced continuously throughout life span
Growth Hormone (GH) by pituitary gland
This hormone is produced continuously throughout the lifespan, and it is responsible for tissue growth, DNA synthesis, and cell duplication
This homone is responsible for early brain growth, metabolism, bone growth, and cell size and deuplication
This hormone is responsible for the changes of puberty in females, though it is also present in smaller amounts in males
This hormone is responsible for the changes of puberty in males, though it is also present in smaller amounts in females
This hormone is found in both genders, bus has little effect on males; it is respnosible for the growth spurt and some of the changes of puberty in females
The major difference between "primary" and "secondary" sex characteristics is:
primary sex characteristics are neccesary for reproducation, while secondary sex characteristics are not
Growth hormone is responsible for:
body tissue growth
What are growth hormones by?
Thyroxine is responsible for:
early brain growth
cell size and duplication
Thyroxine is by :
Estrogen responsible for:
pre-adolscent growth spurt
increased bone density
added body fat
development of females' reproductive organs
regulation of menstrual cycle
estrogen is by:
testosterone and androgens responsible for:
pre-adolescent growth spurt
increased bone density
development of males' reproductive organs
growth of body hair
increased sex drive
testosterone is by:
androgens is by:
over the past 150 years, children in industrialized nations have become _____ and _____, this is due to _____.
taller and heavier
faster rate of development
Children also reach puberty ____ today than in the past
These secular trends of physical growth are the result of _____.
improved health and nutrition
In most nations the secular trend has slowed or stopped, but in the US and a few European countries, higher rates of _____ have led to continued______.
decrease in age of first menstruation
average age of first menstruation (menarche)
12 1/2 years; range 10.5-15.5 years
typically, for 12-18 months no eggs are released
Average age of first ejaculation (spermarche)
typically, early semen contains few living sperm
Females' reactions to changes in puberty?
Today: mixed emotions
prior education and family support are important
Males' reactions to changes in puberty?
generally less informed than females
less likely to tell someone
Higher sex hormones are related to moodiness between the ages of _____, with higher ___ and ____ in males and ___ and ____ in females. Moods are generally ______.
9 and 14
anger and irritability
anger and depression
Generally, adolescents report ______ life events, and during these events are more likely to report ______.
Adolescents respond to negative life events with greater ______.
_______ influences are both evident in adolescents.
situational and hormonal
Compared to younger ages, parent/child relations during adolescence are commonly characterized by:
feeling "less close"
resistance to "family time"
The changes in the parent-child relationship are believed to have ______ significance, as many species reveal "adolescents" leaving "home"
Because humans cannot leave home at puberty, it is thought that a ______ occurs instead of a physical one.
Generally the conflict between parent and child is ____ and ____ continues. Successful families report adapting toward ______ for the child while maintaining _____ that are mutually satisfying.
Early Maturation develment in males:
Late Maturation development in males
Early maturation development in females
popular with boys
Late maturation development in females
for Both sexes, early maturation is linked with:
Long term effects?
earlier sexual activity
Explanation: body image, coping skills, perceived as different
Long term effects: not really
weight loss (25-50%)
do not know they have a problem
harder to treat
binge eating and purging
may not lose weight
more aware of problem
easier to treat
How are anorexia and bulimia similar?
more common in females
middle and upper class families
family or other pressure
pathological fear of gaining weight
There are wide variations in education for and expectations of adolescents on the topic of sexuality. These differences range from:
cultures that expect their teens to engage in sexual activity to cultures who impose the death penalty on teens who have sex.
The US has relatively ____ attitudes regarding teen sexuality. For example, parents typically:
do not discuss sex
Research suggests that teens whose parents discuss sexuality in the context of a warm and open relationship are more likely to adopt their parents' _____ and take fewer ____.
Many parents do not realize where their children will get information about sex if it doesn't come from them. Teens commonly find out about sex from:
One survey of 1500 teens in the US revealed _____% of teens had viewed online pornography in the past ____ months (ages 10 to 17).
Studies revealed that exposure to sexuality on ____ was strongly related to ______.
sexual practice and future intention to have sex
Despite our relatively restricitve attitudes, teens in the US have sex at a ______ age than teens in Canada and Western Europe.
Teens in the US are more likely to have had ______ sexual partners.
Compared to previous generations, attitudes toward sexuality are more _____ among today's adolescents.
A recent conservative trend has been noted among adolescents, perhaps because of concerns about _____
Teens' ____ are often more liberal than their _____.
Most teens in the US have had only _____ sexual partners by the end of high school.
1 or 2
Percentages of high school students reporting ever having sexual intercourse:
Percentage rates by grade level of high school students reporting ever having sexual intercourse:
Characteristics of sexually active teens include:
lack of supervision
lower goals (college)
poverty (Low SES)
sexually active peers/siblings
___ to ____ of sexually active American teens use contraception only occasionally or not at all.
1/3 to 1/2
Reasons teens give for not practicing safe sex included:
concern about others' opinions
too afraid to ask
believe sex should be spontaneous
believe they are invincible
____ to ___% of teens identify themselves as gay, lesbian, or bisexual.
2 to 3
Interviews with homosexual and bisexual youths and adults reveal they commonly experience a 3-phase sequence in achieving their sexual identity:
Gay and lesbian teens often report the following:
efforts to hide their sexual orientation
concerns about what will happen if they tell someone
A cross-cultural study of 500 gay and lesbian teens revealed that ____% had been verbaly abused and ____% had been physically attacked.
_____ of sexually active teens will contract an STD (2.5 million in the US)
______% of all AIDs cases are diagnosed in 20-29 year olds, meaning they contracted the virus during adolescence.
While drug-using and homosexual adolescents account for most cases of AIDS, _____ transfer is greatly increasing.
It is ______ easier for a male to infect a female than for a female to infect a male.
In a cross-cultural comparison, the US is # ______ in teen pregnancies amongst advanced nations
In a cross-cultural comparison, rates of teen pregnancy have recently decreased for the first time in decades, from almost 10% in the 1980s and 1990s to less than ____% today.
_____% of pregant teens in the US have an abortion, and ___% have a miscarriage; thus the rate of teens giving birth and raising children are not higher here than in other countries.
Contributing factors of teen pregnancy:
lack of supervision
lack of parental involvement
_____% of pregnant teens drop out of high school at least temporarily (compared to only 4% of non-pregnant teens)
Most Pregnant teens remain single today(_____% compared to 15% in 1960) and face problems typical of single parents but more pronounced.
Those pregnant teens who do marry because of pregnancy have very high _____
Many teen parents are emotionaly _____ and lack basic____ skills.
Most teen parents have trouble obtaining and maintaining gainful ______; they require ____ or ____ assistance.
Most pregnant teens do not take care of themselves or seek medical attention; thus, rates of _____ are higher
Children of teen parents have higher rates of:
The development of neurons is largely complete by the end of the _____ trimester of pregnancy.
Brain growth beyond birth involves the development of a more intricate system of _____ between neurons.
Neuronal fibers extend to join with neighboring neurons---constantly forming new connections (_______). Stimiluation of neurons promotes additional connective growth.
_____ cells develop rapidly from the 4th month of pregnancy through the 2nd year of life, and then continue to increase gradually. this is responsible for the increases in skull size and brain weight.
At birth, the brain is ____% of its adult weight.
At 6 months, the brain is ____% of its adult weight.
At 2 years, the brain is ____% of its adult weight.
At 6 years, the brain ____% of its adult weight.
two hemispheres have specialized functions
lateralization is underway at birth, and is believed to serve an ____ function (e.g. brain can serve a greater variety of functions); experience speeds this up.
the ability of brain tissue to take over the functions of damaged tissue
brain plasticity is greatest.....
in the 1st years
Stimulus Deprivation (at "Critical stages") leads to ______
slower brain growth (size)
Animals exposed to extreme____ deprivation during postnatal growth spurts had brain degeneration and thus, permanent damage (e.g. kitten kept in darkness never developed sight).
EEG studies of humans suggest that physical brain growth spurts are correlated with advances in cognitive abilites. These spurts have been observed at the following ages:
1.5 to 2 years
18 to 20 years
Evidence for heredity's contribution to physical growth includes:
what is catch up growth?
if growth is stunted temporarily, growth catches up later
Genetics influence our producation of and sensitivity to ______
hormones (inclusing GH)
Genetics influence not only _____ but also body____
The pollutant most commonly studied with regard to child development is ____
lead exposure today is much lower due to reduction of lead in ____ and ___ fumes.
About ____% of low SES children and ____% of African American children living large cintral cities have significant lead levels, likely the result of ......
older homes or neighborhoods near plants that use lead
Early studies on the relationship between lead exposure and cognitive development were flawed; howeve, more recent longitudinal studies have revealed the following outcomes, with cumulative effects, and some appear to be irreversible:
lower verbal skills (lower IQ)
motor skill deficits
Factors that may increase the impact of lead exposure include:
vitamin deficiency (Zinc, Iron)
Over ____% of American mothers breastfeed, which is believed to be the healthiest method of feeding infants.
Reasons for NOT breastfeeding:
Solid foods should be introduced by ____
All basic food groups are needed before _____
Appetite commonly ___ as growth slows (between ages 1 and 2)
Strong preferences for foods commonly emerge in ______
The ____ environment plays a large role in which foods a child will like
Maintaining a _____ mealtime climate is very important.
______ exposure to a new food (without being forced to eat it ) increases the likelihood the child eventually try and like the food.
Bribing children with unhealthy foods lead to _____
In adolescence, rapid growth and changes leads to a dramatic _____ in appetite and eating habits.
Food choices of teens are often _____
_____ are common during adolescence
About ____% of the world's children are undernourished
Extrme malnutrition is liked to:
impaired motor skills
poor strss responses
Obesity is defined as weight that is more than _____% above average body weight based on age, sex and physical build.
Rates of obesity have gradually increased since the ___
About ____ North American children are overweight
there is no link between weight in infancy and later weight problems, but ___% of children who are overweight in middle childhood remain overweight into adulthood.
Factors that contribute to obesity:
early feeding habits
excessive tv viewing
lack of exercise
Consequences of obesity during childhood include:
in developing countries, _____ is a common cause of death in infants and toddlers
such diseases (diarrhea) rarely claim lives in countries where ____ are common
in _____, federal law guaranteed free immunizations to all children in the US; however, ____% of American preschoolers still lack needed immunizations.
Infectious diseases are especially life-threatening when combined with ______.
In extreme cases, children suffer serious _____ as a result of ____.
present by 18 months; characterized by apathy, withdrawal, anxiety; has a wasted appearance despite no biological casue (no serious illness and suffecient food is offered.)
Nonorganic Failure to Thrive
may appear between 2 and 15 years of age; characterized by sub-average stature, wight that is appropriate for height; immature skeletal age, and decreased secretion of GH: GH levels return to normal following removal from emotionally deprived environment.