Self-aggression in macaques: Five case studies

Spontaneous self-aggressive behaviors were observed in five adult male rhesus monkeys (Macaca mulatta ) housed at a university facility. All were individually caged, were free of intercurrent disease, and were utilized in ongoing research studies. The self-aggressive behaviors observed included self-clasping, self-slapping, self-rubbing and threatening of body parts. In several cases, wounds were inflicted and medical treatment was required due to the severity of the lesions. A review of the animals' clinical histories revealed an increased level of self-aggressive behavior in four of five monkeys during such stressful or stimulating conditions as movement of the animal to a new cage, movement of animals out of the room or escape of other monkeys from their cages.