Infants and Stress
Reported September 18, 2008
(Ivanhoe Newswire) — As early as six months of age, parenting can change an infants genetic response to stress. A new study finds parents can have a positive effect even on children who have inherited genetic vulnerabilities to problematic behaviors.
Study authors looked at 142 infants who were separated from their mothers — a stressful situation — when they were three, six and 12 months old. Researchers measured the infants cardiac response to the situation and collected DNA to determine which form of a dopamine receptor gene the infants carried. Specific forms of this gene have been linked to problems in adolescence and adulthood, including aggression and substance abuse, researchers said.
To gauge the mothers behavior as low or high in sensitivity, the studys authors also videotaped the mothers and children playing together when the babies were six months old.
At three and six months, the infants with the genes associated with later risky behaviors did not display an effective cardiac response to the stressful situation, however, the infants without the gene did. At these ages, the researchers did not find a strong link between the mothers behaviors and the infants responses.
However, by 12 months of age, the pattern changed. The infants with the risk gene who had highly sensitive mothers had an effective cardiac response to the stressful situation but those infants with the gene and insensitive mothers did not.
Our findings provide further support for the notion that the development of complex behavioral and physiological response is not the result of nature or nurture, but rather a combination of the two, Cathi Propper, a research scientist at the University of North Carolina-Chapel Hill and the studys lead author was quoted as saying.
SOURCE: Child Development, 2008;79:5