Sociobiology of Rhesus Monkeys Iv: Testing Mason's Hypothesis of Sex Differences in Affective Behavior

Abstract

AbstractDuring a two-year field study of rhesus monkeys, data were obtained that are relevant to a hypothesis, proposed by MASON, GREEN & POSEPANKO (1960), that adult females will show a higher incidence of affective reactions than adult males, including threat behavior and aggressive posturing, and will probably more often be involved in episodes of minor aggression. This hypothesis is here restated in probabilistic terms, and a method is described for quantitative testing of the hypothesis under field conditions. Relevant data from a two-year field study of rhesus monkeys are presented and analyzed. These data gave no indication that females showed a higher incidence of affective responses as a whole, nor that they were more inclined to exhibit the milder forms of agonistic behavior. There was an indication that the affective social behavior of adult males is somewhat more likely to be aggressive than is that of adult females, while the behavior of the adult females is more likely to be submissive. Adult females were more likely to ignore the social partner than were adult males, and were perhaps less likely to lip-smack in affective situations. Among juveniles, the females displayed relatively more affective behavior than did males, as predicted. There was no indication that juvenile females were more likely to ignore their social partner than were males of the same age class. With juveniles, too, there was no indication that the females were more prone to display mild forms of agonism in their affective interactions. While the available data do not confirm the hypothesis of MASON et al., they do support an alternative hypothesis, namely, that in affective behavior, adult males tend, more often than adult females, to lunge, screech, approach, chase, or screech while grimacing, and that females tend, more often than males, to hit, avoid, flee from, or ignore their social partner. Some possible sources of error in this kind of research are discussed; at present the accuracy of generalizations that are made about primate behavior on the basis of field observations is greatly restricted by errors of sampling.