A pair of small, affiliated studies that emerged from the study on the timing of maternal separation were conducted at the Oregon Health and Science University These studies investigated the role played by early experience in determining later behaviors, by examining the modulation of genetic and social influences on behavior in Japanese macaques.
One relevant early life experience in Japanese macaques is a decrease in maternal attention due to mating season or the birth of a new sibling. Factors that could influence individual differences in behavioral reaction to this experience include temperament, biological disposition (behavioral inhibition, growth hormone responsiveness) and social or environmental factors (dominance rank, social support, infant abuse). In humans, socio-economic status (SES) determines access to resources and influences vulnerability to some illnesses. One study examined whether the same may hold true for dominance rank and Japanese macaques.
The study examined whether temperament predicts response to the birth …