AN ASSESSMENT OF EARLY DIFFERENTIAL REARING CONDITIONS ON LATER BEHAVIORAL-DEVELOPMENT IN CAPTIVE CHIMPANZEES

Early rearing experiences have a major impact on later behavioral development in both the human and nonhuman primate. Observation of juvenile chimpanzees (N = 12) reared under four different paradigms were examined to note if a difference existed in affiliative, nonaffiliative, and stereotypical behaviors. The four rearing conditions were defined as either mother-reared by the chimpanzee mother or human hand-reared. The hand-reared were further divided by the following: rearing by a human caregiver in a manner that simulated chimpanzee mother-rearing, simulated chimpanzee mother-rearing but sent away to an alternate institution at age 2 through 3 years, and reared of an alternate institution with limited human interaction. No significant differences were noted in the rearing conditions with the exception of the subjects reared at an alternate institution. These subjects showed significantly more abnormal behaviors than the other three groups. The results may indicate a need for an early strong attachment figure in the chimpanzee's life to alleviate stress and provide adequate behavioral development.