Psychology

To find out if homicide rates would vary as a function of local life expectancy, in Chicago.

A correlation study, using survey data from police records, school records and local demographic records.

Local communities with lower than average male life expectancies.

• Life expectancy was a good predictor of neighbourhood-specific homicide rates.
• Possible that these young men actually discounted the future and expected to live shorter lives, escalating the likelihood that they would increase risk taking for short-term rewards.

• Neighbourhood-specific rate of absenteeism from school was negatively correlated with life expectancy.
• Seeing little point in investing in their futures.

The parents are also operating on a short time horizon and unwilling to enforce attendance because they are aware of homicide rates.

Inequity and unequal distribution of wealth and resources in society mean the poorest feel they have little to lose by engaging in reckless behaviour.