Genetic and Environmental Effects on Conduct and Antisocial Personality Problems in Dutch Twins at Ages 9 to 65 Years

Genetic and Environmental Effects on Conduct and 
Antisocial Personality Problems in Dutch Twins at Ages 9 to 65 Years

The Netherlands Twin Register (NTR) has been using ASEBA forms to assess a large proportion of twins born in the Netherlands since 1986. Many twins have been periodically re-assessed as they developed from childhood to adulthood. Adult twins who joined the NTR have also been re-assessed as they aged. Wesseldijk et al. (2018) analyzed Child Behavior Checklist (CBCL/6-18) scores for twins assessed at ages 9-13, Youth Self-Report (YSR) scores for twins assessed at ages 13-18, and Adult Self-Report (ASR) scores for twins assessed at ages 18-65. The analyses estimated the percentage of genetic and environmental effects on the DSM-Oriented Conduct Problems scale scored from the CBCL/6-18 and YSR and the DSM-oriented Antisocial Personality Problems scale scored from the ASR. Although males scored higher than females at all ages, 43% of the variance in scores was accounted for by genetic effects and 44% by shared environmental effects for both sexes at ages 9-13. At ages 13-18, genetic effects accounted for 49% of the variance in scores, while unique (nonshared) environmental effects accounted for 51% of the variance. At ages 18-65, genetic effects accounted for 43% of the variance, while unique environmental effects accounted for 57% of the variance. Longitudinal correlations between scores at different ages ranged from .20 to .38, due mainly to genetic factors that were stable across ages. The authors concluded “that shared environment is mainly of importance during childhood, while genetic factors contribute to variation in conduct and antisocial personality problems at all ages, and also underlie its stability over age” (p. 1123).

Reference: Wesseldijk, L.W., Bartels, M., Vink, J.M., van Beijsterveldt, C.E.M., Ligthart, L., Boomsma, D.I., & Middeldorp, C. M. (2017). Genetic and environmental influences on conduct and antisocial personality problems in childhood, adolescence, and adulthood. European Child and Adolescent Psychiatry, 27, 1123-1132.