  Antisocial behavior, which includes both aggressive and delinquent
activities, is the opposite of prosocial behavior. Researchers have studied the
heritability of antisocial behavior among twin and non-twin sibling pairs from
behavioral ratings made by parents, teachers, observers, and youth. Through a
meta-analysis, we examined longitudinal and cross sectional research in the
behavioral genetics of antisocial behavior, consisting of 42 studies, of which
38 were studies of twin pairs, 3 were studies of twins and non-twin siblings,
and 1 was a study of adoptees. These studies provided n = 89 heritability (h2)
effect size estimates from a total of 94,517 sibling pairs who ranged in age
from 1.5 to 18 years; studies provided data for 29 moderators (predictors). We
employed a random-effects meta-analysis model to achieve three goals: (a)
perform statistical inference of the overall heritability distribution in the
underlying population of studies, (b) identify significant study level
moderators (predictors) of heritability, and (c) examine how the heritability
distribution varied as a function of age and type of informant, particularly in
longitudinal research. The meta-analysis indicated a bimodal overall
heritability distribution, indicating two clusters of moderate and high
heritability values, respectively; identified four moderators that predicted
significant changes in mean heritability; and indicated differential patterns
of median h2 and variance (interquartile ranges) across informants and ages. We
argue for a cross-perspective, cross-setting model for selecting informants in
behavioral genetic research, that is flexible and sensitive to changes in
antisocial behavior over time.
