Agonistic Behavior of Pregnant Female Monkeys (Macaca Nemestrina): Possible Influences of Fetal Gonadal Hormones

Abstract

15 pregnant female monkeys ( Macaca nemestrina) were observed and the frequencies of 14 categories of agonistic behavior were recorded. Predictions of sex of fetus were based on relative frequencies of aggressive and submissive behaviors. Correct predictions were made in 11 of 15 cases (P < .06). The relative aggressiveness of females carrying male fetuses (by contrast with those carrying female fetuses) suggests that the secretion of androgens by male fetuses may masculinize the behavior of the female host.