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Behavioral, biological, and epigenetic consequences of different early social experiences in primates

Stephen J. Suomi, PhD, Chair, Lab­o­ra­tory of Com­par­a­tive Ethology, Eunice Kennedy Shriver National Insti­tute of Child Health and Human Development, National Insti­tutes of Health   Web­site  |  Pub­li­ca­tions

Abstract: Early social expe­ri­ences can have last­ing effects on pri­mate bio-behavioral devel­op­ment, espe­cial in the con­text of sub­se­quent social stress. For exam­ple, rhe­sus mon­keys raised in the absence of their bio­log­i­cal mother (but with access to peers) or raised by neglect­ful moth­ers show rel­a­tively nor­mal bio-behavioral devel­op­ment when sub­se­quently main­tained in benign social envi­ron­ments, but under socially stress­fully cir­cum­stances, e.g., social sep­a­ra­tion, they typ­i­cally exhibit exces­sive fear­ful­ness and/or aggres­sion, height­ened HPA activ­ity, and reduced sero­tonin metab­o­lism into adult­hood. More­over, they dif­fer from mon­keys not expe­ri­enc­ing such early social adver­sity in both brain struc­ture and func­tion. Some of these char­ac­ter­is­tics appear to be trans­mit­ted to their off­spring via non-genetic (most likely epi­ge­netic) mech­a­nisms. Recent tech­no­log­i­cal advances in genomics have made it pos­si­ble to exam­ine genome-wide expres­sion, and pre­lim­i­nary analy­ses sug­gest that such adverse early expe­ri­ences affect approx­i­mately one fifth of the entire rhe­sus mon­key genome (more than 4,400  indi­vid­ual genes), both in the brain and in white blood cells. Given that many of the behav­ioral and bio­log­i­cal con­se­quences of adverse early social expe­ri­ence are largely reversible fol­low­ing tar­geted envi­ron­men­tal inter­ven­tions, the ques­tion of whether the pat­terns of gene expres­sion in these mon­keys are also reversible is under intense cur­rent investigation.

Bio: Stephen J. Suomi, Ph.D. is Chief of the Lab­o­ra­tory of Com­par­a­tive Ethol­ogy at the Eunice Kennedy Shriver National Insti­tute of Child Health and Human Devel­op­ment (NICHD), National Insti­tutes of Health (NIH) in Bethesda, Mary­land. He also holds research pro­fes­sor­ships at the Uni­ver­sity of Vir­ginia, the Uni­ver­sity of Mary­land, Col­lege Park, the Johns Hop­kins Uni­ver­sity, George­town Uni­ver­sity, the Penn­syl­va­nia State Uni­ver­sity, Amer­i­can Uni­ver­sity, and the Uni­ver­sity of Mary­land, Bal­ti­more County. Dr. Suomi earned his B.A. in psy­chol­ogy at Stan­ford Uni­ver­sity in 1968, and his M.A. and Ph.D. in psy­chol­ogy at the Uni­ver­sity of Wisconsin-Madison in 1969 and 1971, respec­tively. He then joined the Psy­chol­ogy fac­ulty at the Uni­ver­sity of Wisconsin-Madison, where he even­tu­ally attained the rank of Pro­fes­sor before mov­ing to the NICHD in 1983.

Dr. Suomi’s ini­tial post­doc­toral research suc­cess­fully reversed the adverse effects of early social iso­la­tion, pre­vi­ously thought to be per­ma­nent, in rhe­sus mon­keys. His sub­se­quent research at Wis­con­sin led to his elec­tion as Fel­low in the Amer­i­can Asso­ci­a­tion for the Advance­ment of Sci­ence “for major con­tri­bu­tions to the under­stand­ing of social fac­tors that influ­ence the psy­cho­log­i­cal devel­op­ment of non­hu­man pri­mates.” His present research at the NICHD focuses on 3 gen­eral issues: the inter­ac­tion between genetic anden­vi­ron­men­tal fac­tors in shap­ing indi­vid­ual devel­op­men­tal tra­jec­to­ries, the issue of con­ti­nu­ity vs. change and the rel­a­tive sta­bil­ity of indi­vid­ual dif­fer­ences at mul­ti­ple lev­els of analy­sis through­out devel­op­ment, and the degree to which find­ings from mon­keys stud­ied in cap­tiv­ity gen­er­al­ize not only to mon­keys liv­ing in the wild but also to humans liv­ing in dif­fer­ent cultures.

Through­out his pro­fes­sional career Dr. Suomi has been the recip­i­ent of numer­ous awards and hon­ors, the most recent of which include the Don­ald O. Hebb Award and a Pres­i­den­tial Cita­tion from the Amer­i­can Psy­cho­log­i­cal Asso­ci­a­tion, the Dis­tin­guished Pri­ma­tol­o­gist Award from the Amer­i­can Soci­ety of Pri­ma­tol­o­gists, and the Arnold Pff­ef­fer Prize from the Inter­na­tional Soci­ety of Neu­ropsy­cho­analy­sis. To date, he has authored or co-authored over 400 arti­cles pub­lished in sci­en­tific jour­nals and chap­ters in edited volumes.