1250 



HORMONAL REGULATION OF BEHAVIOR 



more punishment but almost never caused 

 aggression. It was concluded that dominance 

 sti-ongly modified the effect of frustration 

 in causing aggression, and that frustration 

 caused aggression in situations in which ani- 

 mals were in the habit of being aggressive. 

 In goats there was no fighting and no domi- 

 nance when they were given plenty of food 

 scattered about to prevent crowding while 

 feeding. 



In mice hunger and thirst did not affect 

 the tendency to fight (Ginsburg and Allee, 

 1942), nor did vitamin Bi deficiency cause 

 a loss of social status in high ranking indi- 

 viduals until they were in an advanced 

 stage of avitaminosis (Beeman and Allee, 

 1945). Aggressive behavior was not affected 

 until the individual was physically weak- 

 ened, and staged pair contacts were strongly 

 influenced by psychologic factors. In the 

 chaffinch (Marler, 1955) starvation, how- 

 ever, reduced the tendency of subordinates 

 to avoid dominant individuals. Inasmuch 

 as females are less aggressive than males, 

 and avoidance reactions are less intense, the 

 toleration which developed toward low 

 ranking individuals was more pronounced 

 in female flocks. In rats Hall (1936) found 

 that nonhungry individuals display greater 

 emotionality than do hungry rats. He con- 

 cluded that ''needs, other than the need to 

 escape, inhibit the display of emotional be- 

 havior by distracting the animal from the 

 fear-provoking aspects of the situation." 



Among birds there are a number of situa- 

 tions in which two or more drives are in con- 

 flict. The conflict may be between aggressive 

 and sexual activities, or between attacks 

 and escape behavior. What makes the con- 

 flict apparent is that sometimes the re- 

 sultant pattern of behavior is atypical of the 

 drives in conflict. These patterns are called 

 displacement activities and have been vari- 

 ously named and defined. According to 

 Bastock, Morris and Moynihan (1953) "dis- 

 placement activities apparently can occur 

 in two situations. (1) Displacement ac- 

 tivities may be performed by an animal in 

 which two or more incompatible drives are 

 strongly activated; each drive prevents the 

 expression of the other (s). (2) Displace- 

 ment activities may also be performed by 

 an animal in which one drive is, at the 



same time, both activated and thwarted." 

 A number of such conflicting situations is 

 mentioned by Armstrong (1947, pp. 99- 

 lOlj. 



An interesting study of the conflict be- 

 tween the tendencies of attacking, fleeing, 

 and courting in the male chaffinch was made 

 by Hinde (1953). The male is dominant 

 over the female in winter, and in the spring 

 the dominance is reversed. The male's dis- 

 play occurs in those situations in which his 

 tendencies to approach (court) and to flee 

 from the female are in approximate balance. 

 A similar analysis can be applied to the 

 female. Attempts to copulate may be un- 

 successful if the sex drives of both indi- 

 viduals are not sufficient to inhibit aggres- 

 sive behavior. 



The presentation of the material which 

 follows is given with the assumption that 

 the many factors enumerated above have 

 been controlled. 



VI. Gonadal Hormones and 

 Social Behavior 



A. SOCIAL BEHAVIOR AND THE 

 REPRODUCTIVE CYCLE 



The stimulating action of gonadal hor- 

 mones on social behavior might long ago 

 liave been postulated from the close re- 

 lationship between reproductive state and 

 behavior, in wild species in which reproduc- 

 tion is generally seasonal, and in many 

 laboratory and domesticated species in 

 which cyclic activity is continuous without 

 intervening periods of anestrum. Relation- 

 ships of this sort are well known in birds 

 (Armstrong, 1947) and many mammals: the 

 red deer, Cervus elaphus (Darling, 1937), 

 the wapiti, Cervus canadensis, the moose, 

 Alces americana shirasi, the chamois, Rwpi- 

 capra rupicapra, the wild boar, Sus scrofa 

 europ. (Altmann, 1952, 1956), and others. 

 Territorialism may develop during the 

 breeding cycle among frogs (Martof, 1953; 

 Test, 1954) and reptiles (Greenberg and 

 Noble, 1944). In fish, seasonal modification 

 in breeding aggregations has been described 

 by Aronson ( 1957 ) . It is common knowledge 

 that the males of many species show com- 

 bative behavior during the breeding season. 

 Rowan (1931) observed that the male bobo- 



