Early life stress moderates the relationship between age and prosocial behaviors

Several studies suggest that prosocial behaviors gradually increase with age, but others report that prosocial behaviors are fixed traits with only minor fluctuations throughout the lifespan. Early life stress may help explain these inconsistencies, as distinct types of stress have been negatively or positively associated with prosocial behaviors.

This current investigation used two studies to test whether distinct types of early life stress moderated the association between age and prosocial behavior.

Study 1 recruited undergraduate students (n = 69) between the ages of 18-35, and Study 2 was conducted on Amazon Mechanical Turk responders (n = 499) whose ages ranged from 18-74.

Study 1 employed behavioral economic tasks to measure cooperation and charitability, while Study 2 utilized an online survey to measure helping attitudes.

Moderation analyses revealed the association between age and cooperation was significantly weakened by a history of family violence (β=-0.37,p = 0.002), community violence (β=-0.30,p = 0.012), emotional abuse (β=-0.27,p = 0.026), and an overall summary score of early life stress (β=-0.33,p = 0.006). The relationship between age and charitability was only weakened by family violence (β=-0.24,p = 0.048). The association between age and helping attitudes was weakened by family violence (β=-0.10, p = 0.023), community violence (β=-0.13,p = 0.003), and physical neglect (β=-0.11,p = 0.018).

Collectively, these results suggest that some types of early life stress, especially exposure to violent environments, may reduce the likelihood of prosocial behaviors increasing throughout the lifespan. This study suggests that age-related effects on prosocial behaviors may not be universal, but rather depend on individual differences in childhood stress.