Source
Social Genetic and Developmental Psychiatry Centre, P080, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. e.viding@iop.kcl.ac.uk.
Abstract
BACKGROUND:
A callous and unemotional disposition is an indicator of early-onset antisocial behaviour.
AIMS:
To investigate the extent to which genetic influences contribute to the overlap between callous-unemotional traits and conduct problems in a large population sample of 7-year-old twins.
METHOD:
Teachers provided ratings of callous-unemotional traits and conduct problems for 3434 twin pairs from the Twins Early Development Study. Model-fitting analyses were performed across the continuum of scores and at the extremes.
RESULTS:
The phenotypic relationship was primarily genetically mediated, both across the continuum and at the extremes and was substantial.
CONCLUSIONS:
At 7 years of age, genetic influences on callous-unemotional traits overlap substantially with genetic influences on conduct problems. This combination should guide selection criteria in future molecular genetic studies.