Hallucinogen-induced behaviors of free-moving chimpanzees

Abstract

The effects of the hallucinogen N,N-dimethyltryptamine (DMT) on the behavior of two island groups of four champanzees each were studied. One target animal from each group was selected for treatment and individual and social behaviors were scored according to a quantitative observational system. Low doses of DMT (.5-3.0 mg/kg) caused dose-dependent increases in duration of vocalization, fear grimace, and locomotion. Higher doses (4.0 mg/kg) tended to decrease these behaviors as well as others such as self-grooming. Social aggregation tended to decrease with increasing doses, and social interactions between target animals and others were rare. Results tended to support the hypothesis that hallucinogens increase social spacing and isolation. © 1977, The psychonomic soceity, inc. All rights reserved.