Biologists at the Federal University of Pernambuco in Brazil observed a capuchin masturbating while looking at sexual interactions. work published In Archives of Sexual Behavior.
Between January and October 2014, scientists observed a captive colony of 17 bearded capuchins. During that time, the researchers recorded 11 sexual acts, 68 attempts at intercourse, and five acts of masturbation. Only one of the men masturbated, doing so three times by observing the behavior of the other monkeys.
“The same low-ranking male named Fu looked at other monkeys participating in the sexual performances and masturbated three times. The process took an average of 2 minutes and 40 seconds,” he said.
Observations suggest that visual sexual stimuli can trigger masturbation in capuchin monkeys. The male’s low hierarchical ranking and the consequent lack of mating opportunities in the newly formed group may have triggered masturbation.