This twin study examined the structure of genetic and environmental influences on aggression and rule-breaking in order to examine change and stability across the span of childhood to mid-adolescence.

Previous studies that have explored the relationship between parenting style and children’s antisocial behavior have generally found significant bidirectional effects, whereby parenting behaviors influence their child’s antisocial outcomes, but a child’s behaviors also lead to changes in...

The Southern California Twin Register was initiated in 1984 at the University of Southern California, and continues to grow. This paper provides an update of the register since it was described in the 2002 special issue of this journal. The register has expanded considerably in the past four...