Sexual behavior in adult gonadectomized female pseudohermaphrodite, female, and male rhesus macaques (Macaca mulatta) treated with estradiol benzoate and testosterone propionate.

Studies were made of the sexual behavior of 22 gonadectomized adult rhesus macaques (Macaca mulatta) given no hormonal treatment, treated with estradiol benzoate (EB, 20 microgram/day), and treated with testosterone propionate (TP, 10 mg/day). Experimentally produced female pseudohermaphrodites (hermaphrodites, n = 6), long-term castrated males (n = 9), and ovariectomized females (n = 7) were given 36 pair tests of 10-min duration with ovariectomized, estrogen-primed female partners. Twelve tests were given under each treatment condition. Yawning was the only behavior that showed a significant effect across treatments for hermaphrodites and females; the yawning rate was greater with TP treatment. The number of tests during which hermaphrodites showed erections increased significantly under TP treatment. One hermaphrodite mounted, but none achieved intromission or ejaculated. Males displayed several significant treatment effects, including increased mounting, intromitting, and ejaculating frequencies under TP treatment. The EB had little effect on any of the behaviors in any group. Rates of aggression and grimacing were greater among hermaphrodites than among males and females. Males displayed significantly greater rates of sexual behavior than hermaphrodites or females. As infants and juveniles, these hermaphrodites had displayed social and sexual behavior characteristic of males, but as mature adults, their behavior and responsiveness to testosterone at a dose capable of activating a high level of sexual behavior in castrated males gave little evidence of masculinization.