VCU Study: Genetic factors may influence common fears

By Sathya Achia Abraham

As we move from childhood to young adulthood, the genes that influence our common fears of rats, the dark, or flying change considerably over time rather than staying static, according to a new study by Virginia Commonwealth University researchers.

The results of the research, led by Kenneth S. Kendler, M.D., professor of psychiatry and human genetics in VCU's School of Medicineare reported in the April 7 issue of the journal Archives of General Psychiatry.

"The genome is a dynamic place," said Kendler. "Evolution has likely shaped our genomes to adapt to changing developmental situations. For example, what an 8-year-old child should be afraid of is not the same as that of a 20-year-old young adult. Our genome reflects that difference."

VCU researchers, together with researchers from the Karolinska Institute and Uppsala University in Sweden, evaluated fear factors among 2,500 twin pairs born between 1985 and 1986. The twin pairs were from the Swedish Twin Study of Child and Adolescent Development.

All participants completed a questionnaire containing 13 items regarding fear of particular situations, animals and blood or injuries. Participants were asked to rate the intensity of fear on a scale from 0 (no fear) to 10 (maximal fear). Additionally, their parents were asked to rate their child's fear intensity using the same scale. The sample was assessed at ages 8-9, 13-14, 16-17 and 19-20.

The study was supported in part by the National Institute of Mental Health, the Swedish Council for Working Life and Social Research and the Swedish Research Council.

Collaborating with Kendler were VCU researchers Charles Gardner, Ph.D., Lindon Eaves, Ph.D., DSc., Michael Neale, Ph.D; Peter Annas, Ph.D., with Uppsala University in Sweden; and Paul Lichtenstein, Ph.D., with the Karolinska Institute in Stockholm Sweden.