Vol. 7, No. 1, 2001 Page 7 
|
Vol. 7, No. 1, 2001 Page 7 |
A new twin study supports earlier findings of a strong genetic component to aggression, and also shows that genes play a powerful role in anxiety, depression, and inattentiveness.
James Hudziak et al. studied 492 twin pairs, asking one parent of each twin pair to fill out the Child Behavior Checklist. To distinguish between environmental and hereditary influences, the researchers compared identical (monozygotic) and fraternal (dizygotic) twins.
The researchers report that "estimates of genetic influences on attention problems (60 to 68 percent), aggression (70 to 77 percent), and anxious/depressed behaviors (61 to 65 percent) were high for both sexes," and indicate that "at least half of the variability in these syndromes is attributable to genetic influences."
Hudziak et al.'s findings are similar to those of Philip Vernon et al. (see related article, Crime Times, 2000, Vol. 6, No. 4, Page 5), who reported "moderate to quite large heritabilities" for aggressive behavior, and to research by J.C.G. van den Oord et al. (see related article, Crime Times, 1995, Vol. 1, No. 3, Page 6), who found that "genetic influences accounted for 70 percent of the variance of aggressive behavior."
"A twin study of inattentive, aggressive, and anxious/depressed behaviors," James J. Hudziak, Lawrence P. Rudiger, Michael C. Neale, Andrew C. Heath, and Richard D. Todd, Journal of the American Academy of Child and Adolescent Psychiatry, Vol. 39, 2000, pp. 469-476. Address: James Hudziak, University of Vermont, Given Bldg., Rm. B229, Burlington, VT 05405, jhudziak@zoo.uvm.edu.