Individual differences in temperament and behavioral management

As anyone working with captive nonhuman primates is keenly aware, individual primates can differ vastly with respect to their behavioral responses to stressful or novel stimuli. Walk into a room of unknown rhesus macaques, and you will undoubtedly be greeted with an array of responses, from threats to fear grimaces to seeming indifference. There are many reasons for these disparate behavioral responses, including past experience, current emotional state, and the stimulus itself. However, one of the major forces underlying these different reactions is biological predisposition or temperament. Once considered “noise” around an adaptive mean (Francis 1990), these individual differences in temperament are now generally accepted as interesting and important in their own right (Clark and Ehlinger 1987).