Abstract :
Although genetic and environmental factors are
separately implicated in the development of antisocial
behavior (ASB), interactive models have emerged relatively
recently, particularly those incorporating molecular genetic
data. Using a large sample of male Caucasian adolescents
and young adults from the National Longitudinal Study of
Adolescent Health (Add Health), the association of deviant
peer affiliation, the 30-base pair variable number tandem
repeat polymorphism in promoter region of the monoamine
oxidase-A (MAOA) gene, and their interaction, with
antisocial behavior (ASB) was investigated. Weighted
analyses accounting for over-sampling and clustering
within schools as well as controlling for age and wave
suggested that deviant peer affiliation and MAOA genotype
were each significantly associated with levels of overt ASB
across a 6-year period. Only deviant peer affiliation was
significantly related to covert ASB, however. Additionally,
there was evidence suggestive of a gene-environment
interaction (G × E) where the influence of deviant peer
affiliation on overt ASB was significantly stronger among
individuals with the high-activity MAOA genotype than the
low-activity genotype. MAOA was not significantly associated
with deviant peer affiliation, thus strengthening the
inference of G × E rather than gene-environment correlation
(rGE). Different forms of gene-environment interplay and
implications for future research on ASB are discussed.
