At 12 years of age, participants were asked to report on the level of antisocial behavior within their peer group with respect to five characteristics: “get into fights with other kids,” “use bad language,” “lie to their parents and teachers,” “get into trouble at school,” “like to do things that make you scared or uncomfortable.” Each of the behaviors was rated on a 5-point ordinal scale that ranged from “they never do this” to “they do this very often,” and values were summed across these five items (α = .74) and divided by the total number of items for which there were responses to derive an overall measure of peer group antisocial behavior. Age 12 assessments were used to examine peer group influences on contemporaneous externalizing behavior, as well as subsequent development within this construct, as these data were not available at earlier waves.
