Laboratory of Comparative Ethology, National Institute of Child Health & Human Development, National Institutes of Health, DHHS, Bethesda, Maryland 20892-7971, USA
Address for correspondence: Dr. Stephen J. Suomi, Ph.D., Laboratory of Comparative Ethology, NICHD, NIH, DHHS, 6705 Rockledge Drive, Suite 8030, Bethesda, MD 20892-7971. Voice: 301-496-9550; fax: 301-496-0630. ss148k{at}nih.gov
Ann. N.Y. Acad. Sci. 1008: 132-139 (2003).
Recent research has disclosed marked individual differences
in biobehavioral responses to social conflicts exhibited by
rhesus monkeys across the life span. For example, approximately
5-10% of rhesus monkeys growing up in the wild consistently
exhibit impulsive and/or inappropriately aggressive responses
to mildly stressful situations throughout development; those
same individuals also show chronic deficits in their central
serotonin metabolism. These characteristic patterns of biobehavioral
response emerge early in life and remain remarkably stable from
infancy to adulthood. Laboratory studies have demonstrated that
although these characteristics are highly heritable, they are
also subject to major modification by specific early experiences,
particularly those involving early social attachment relationships.
Moreover, genetic and early experience factors can interact,
often in dramatic fashion. For example, a specific polymorphism
in the serotonin transporter gene is associated with deficits
in early neurobehavioral functioning and serotonin metabolism,
extreme aggression, and excessive alcohol consumption among
monkeys who experienced insecure early attachment relationships,
but not in monkeys who developed secure attachment relationships
with their mothers during infancy. Because daughters tend to
develop the same type of attachment relationships with their
own offspring that they experienced with their mothers early
in life, such early experiences provide a possible nongenetic
mechanism for transmitting these patterns to subsequent generations.
