The company we keep may be more influenced by genetics than previously thought. Researchers report that as individuals develop, genes become more important in influencing how they choose their peer groups. The findings offer insight into which individuals may be at risk for future substance use or other externalizing behaviors such as conduct and antisocial personality disorder.
The study involved 1,800 male twin pairs from mid-childhood to early adulthood, between 1998 and 2004.
Through a series of interviews, researchers found that genetic factors increasingly impact how male twins make choices as they mature and develop their own social groups. Their finding include that the path from genes to behaviors like drug use and antisocial behaviors is not entirely direct or biological. Rather an important part of this pathway involves the genetics, which influences our own social environment, which in turn impacts on our risk for a whole host of deviant behaviors. Results demonstrate clearly that a complete understanding of the pathway from genes to antisocial behaviors, including drug abuse, has to take into account self-selection into deviant versus benign environments. The effects of peers in adolescence can be quite powerful, either encouraging or discouraging deviant behaviors. Peers also provide access to substances of abuse.