The social development of a female rhesus monkey was followed from birth until death, age 32 months. The monkey had an extra autosome and was hydrocephalic. The monkey showed serious motor deficiencies, delayed social development, poorly established dominance relationships, and heavy dependence on mother and kin. The monkey was, however, well…

Four studies involving 40 pigtail monkeys are described in which relatively short separation experiences in infancy were associated with evidence of persistent changes in social behavioral function (less sociability, fewer close friends) and immunological function (suppression of lymphocyte proliferation) up to 6 years later. (Author/JDD)