Consort bonding and operant behavior by female rhesus monkeys.

Abstract
An operant conditioning situation was used to relate the lever-pressing performance of female rhesus monkeys to different measures of social, sexual and agonistic behavior that underlie the formation and dissolution of consort bonds. Nine females were trained to press a lever 250 times to gain access to a male partner. After access, a standard 60 min behavioral test took place (1440 tests). Data were analyzed independently of the stage of the menstrual cycle. Eight females were tested with 2 males, and every female gained access faster with 1 male (preferred partner). For all 8 females, the preferred male was the one that spent more time grooming the female. For 5 females, the preferred partner was also the one that ejaculated more frequently. For 4 females, where agonistic interactions with males could be evaluated, the preferred male was the one that elicited fewer submissive behavioral patterns. The operant behavior of female rhesus monkeys was positively reinforced by social and sexual factors and negatively reinforced by agonistic interactions and may provide a measure of the strength of consort bonds.