Epigenetic rules in moral development: Distal-proximal approaches to altruism and aggression

The nature of nurture: Genetic influence on “environmental” measures

Evidence for genetic influence on environmental measures will emerge in quantitative genetic analyses if genetically influenced characteristics of individuals are assessed by these environmental measures. Recent twin and adoption studies indicate substantial genetic influence when measures of the environment are treated as phenotypes in genetic analyses. Genetic influence has been documented for measures as diverse as videotaped observations of parental behavior toward their children, ratings by parents and children of their family environment, and ratings of peer groups, social support, and life events. Evidence for genetic influence on environmental measures includes some of the most widely used measures of environment – the Home Observation for Measurement of the Environment, the Family Environment Scales, and the Social Readjustment Rating Scale of life events, for example. The goal of this article is to document and discuss these findings and to elicit commentary that might help to shape the course of research on this topic, which has far-reaching implications for the behavioral and brain sciences.

THE EFFECTS OF INTERPERSONAL TRUST AND GROUP STATUS ON PROSOCIAL AND AGGRESSIVE BEHAVIORS

Preliminary evidence suggests that interpersonal trust is associated with both aggression and prosocial behavior, but little research has been conducted to investigate these relationships in nonclinical samples. It has been suggested by Scott (1980) that general trust is not as useful in predicting behavior in organizational settings as is situational trust. However, if moderated by in-group - out-group status, general trust may be useful in predicting general response tendencies such as aggressive and prosocial behaviors. Building on the norm of reciprocity as described by Kaufmann (1970) and Rushton (1980), it was hypothesized that: a) subjects identified as high trusters would show low levels of aggression and high levels of prosocial behaviors towards both in- and outgroup members; b) low trusters would show high levels of aggression and low levels of prosocial behavior towards both in- and out-groups members; and c) moderate trusters would show lower levels of aggression towards the in-group than towards the outgroup and higher levels of prosocial behavior towards the in-group than towards the out-group. These hypotheses were not confirmed. Participants reported higher levels of prosocial behavior towards the in-group than towards the out-group, regardless of the level of trust. Group differences also emerged on the aggression measures regardless of trust level. Trend analyses revealed that as trust h∼creases, overall prosocial behavior increases.