Genetic
and environmental influences on problem behaviors in 5-year-old DUTCH twins
C.E.M.
van Beijsterveldt1,2, F. Verhulst2, D.I. Boomsma1
1 Dept
of Biological Psychology, Vrije Universiteit, The Netherlands.
2
Erasmus
Universiteit Rotterdam, The Netherlands
Problem
behaviors in young children do not form clearcut diagnostic categories, but
involve quantitative variations of behavior that most children display to some
degree. It is therefore preferable to examine genetic influences on
psychopathology assessed as quantitative variations of behavior rather than a
present-vs-absent diagnosis. For this purpose standardized ratings of problem
behavior filled in by parents may be a good source of information of child
psychopathology. In the present study behavior problems were assessed with
items from the Devereux Child Behavior (DCB) rating scale (Spivack and Spotts,
1966) filled in by the parents. The rating yielded 5 problem scales:
aggression, distraction, anxiety, physical coordination, and inability to
delay. The sample consisted of 3600 5-year-old twin pairs. Structural equation
models were used to examine the contribution of genetic and environmental
factors on problem behavior. Univariate genetic analyses yielded large
additive genetic effects for all problem scales. We found heritabilities
ranging from .50 to .80. Shared environmental effects were only significant
for aggression and anxiety and explained a much smaller part of the variance.
Test of sex differences showed no significant results.
Supported
by grant 904-57-094 from the Netherlands Organization for Scientific Research
(NWO)