GONADAL HORMONES AND SOCIAL BEHAVIOR 



125: 



Birch (1945) state that estrogens increase 

 the aggressiveness and dominance tendency 

 of female chimpanzees and that the grant- 

 ing-of-privilege concept is superfluous. 



Certain circumstances should be noted in 

 any consideration of these latter studies. 

 Only three females were used and Yerkes 

 and Crawford had observed much variabil- 

 ity in their experiments. Further, the sub- 

 jects had been ovariectomized postpuber- 

 tally and had been together intermittently 

 for several years. The dominance order was 

 Lia, Nira, May. Nira was paired with Lia 

 in a food competition situation before, dur- 

 ing, and after treatment, and May was 

 tested similarly in pairings with both of her 

 social superiors. Nira obtained higher com- 

 petition scores during treatment, whereas 

 May failed to show any changes. Before 

 ovariectomy. May mated readily with the 

 males when she was in the swelling phase, 

 whereas Nira during 5 years as a mature 

 female had been known to copulate only 

 once despite frequent attempts to breed her. 

 Two questions arise: Did Nira's failure to 

 breed before ovariectomy indicate abnor- 

 mality? Did agonistic experiences before 

 ovariectomy augment or suppress any prob- 

 able effects of estrogenic treatment? 



D. ARE AGGRESSIVENESS AND SUBMISSIVENESS 

 SEPARATE BEHAVIOR PATTERNS? 



Before leaving the subjects of estrogens 

 and submissiveness, and androgens and ag- 

 gressiveness, the alternative possibilities 

 must be considered that these antithetical 

 behaviors are (1) independent tendencies 

 or (2) extremes on the same scale of social 

 interactions. As a starting point for the dis- 

 cussion, the reader will be reminded that, 

 except for the claim by Birch and Clark 

 that estrogens increase the aggressiveness of 

 the female chimpanzee, opinion is general 

 that dominance is lowered (or submissive- 

 ness is increased) by these hormones (Col- 

 lias, 1944; Beach, 1948). To the holder of 

 this view who also accepts the conclusion 

 that androgens enhance aggressiveness, it 

 is only a step to the hypothesis that aggres- 

 siveness and submissiveness are independent 

 traits, that aggressiveness is essentially but 

 by no means exclusively masculine and sub- 

 missiveness essentiallv but bv no means ex- 



clusively feminine. But the alternative con- 

 cept that aggressiveness and submissiveness 

 are merely opposites on the same scale of 

 social interactions must be considered. Sup- 

 {)ort for such an opinion might come from 

 the fact that both types of reaction are 

 shown by the same individual in appropri- 

 ate situations. However, this is also true of 

 sexual behavior, but in the case of sexual 

 behavior, a rather convincing body of evi- 

 dence has accumulated that two mecha- 

 nisms are involved (for a review of the 

 subject see the chapter by Young, and for 

 new data obtained during an investigation 

 of the patterns of inheritance of masculine 

 and feminine behavior in female guinea pigs 

 see Goy and Jakway, 1959). A solution of 

 the problem may come from further work 

 with gamecocks which have been selected 

 for persistence in fighting and may fight to 

 the death without showing avoidance be- 

 havior. It was a strain of guinea pigs (strain 

 2), in which the females normally display 

 little or no masculine behavior, that 

 provided the genetical evidence for the inde- 

 pendence of masculine and feminine com- 

 ponents of sexual behavior (Goy and Jak- 

 way, loc. cit.). 



E. GONADAL HORMONES AND THE 



DEVELOPMENT OF SOCIAL 



BEHAVIOR 



A discussion of the development of social 

 behavior should be related to the heredity- 

 environment or instinct-learning contro- 

 versy, which, however, is beyond the scope 

 of this chapter. Should there be a need for 

 references to recent views on this subject, 

 several publications are available (Tin- 

 bergen, 1951; Lehrman, 1953; and Emlen, 

 1955). Some observational studies on the 

 socialization of young animals have been 

 reported for birds (Collias, 1952), mice 

 (Williams and Scott, 1953), sheep (Scott, 

 1945), sheep and goats (Collias, 1956), and 

 dogs (Scott and Marston, 1950) . Most of the 

 experimental studies have been focused on 

 the precocious display of sexual behavior 

 and are discussed in the chapter by Young. 



Collias (1950) began treatment of male 

 and female domestic chicks with testoster- 

 one and estradiol when they were 2 days 

 old. Dosages of 0.1, 0.3, 0.5, and 0.7 mg. of 



