A common topic for parents is whether their genetics or their behaviors are more influential in shaping their children. A study by University of Wisconsin researchers found a bridge between those two -- that parent stress has a lasting impact on the genetic composition of their kids.

The report, published this week in the journal Child Development, is part of the ongoing observation of 500 children from Madison and Milwaukee. Researchers from UW and the University of British Columbia found a chemical reaction called methlyation -- which regulates or inhibits genetic expressed -- was more common in the DNA of adolescents whose parents reported high levels of stress when their kids were young.

"This is very exciting because we've shown that day-to-day stress in early childhood can predict changes in DNA that can be observed in adolescence," said Dr. Marilyn Essex, a professor of psychiatry at the UW School of Medicine and Public Health. "It's further proof of the importance of those early years and the lasting effects of children's family environments during infancy and preschool."

The researchers found that stress levels in fathers were more strongly related to DNA methylation in daughters, while stress levels in mothers were associated with both boys and girls. Interestingly, the DNA affected by high parental stress levels are not the DNA known to play a role in influencing a person's behavior or reaction to external stress. The study is nonetheless one of the first to link early childhood stress with how genes express themselves in adolescents.

So maybe it's not nature or nurture, but nature AND nurture.