Young monkeys reared by a mother other than their own are more likely to exhibit the aggressive or friendly behavior of their birth mothers rather than the behavior of their foster mothers, a University of Chicago researcher has shown for the first time.

The discovery of inheritability of social behavior traits among non-human primates has important implications for people as it reinforces other research that suggests that such characteristics as sociability and impulsive aggressiveness among humans may have a genetic basis, said Dario Maestripieri, Associate Professor in Human Development at the University. The work with monkeys may help other researchers understand the biological origins of characteristics that promote socialization among humans, he said.

His work on monkeys is reported in the article "Similarities in Affiliation and Aggression Between Cross-Fostered Rhesus Macaque Females and Their Biological Mothers," published in the current issue of Developmental Psychobiology.

Rhesus macaques provide an important research population because they organize in strong matrilineal structures, and the female offspring often exhibit the same social behavior as their mothers. The experiment was intended to show if some aspects of that behavior were inherited or learned by the female offspring.

"I was surprised by what we found," Maestripieri said. Scholars have felt that social learning from the mother would play an important role in the development of female social behavior from early infancy. The study shows that inherited behavioral predispositions are probably more important.

For the study, Maestripieri and his colleagues swapped rhesus monkey female babies between mothers who had recently given birth. These adoptions are typically difficult to achiev
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Contact: William Harms
w-harms@uchicago.edu
773-702-8356
University of Chicago Medical Center
3-Dec-2003