1244 



HORMONAL REGULATION OF BEHAVIOR 



flock or between flocks (Giihl and Allee, 

 1944). The degree of domination or sub- 

 ordination of a hen may be measured by 

 the number of individuals it pecks or avoids. 

 The top-ranking hen habitually pecks all 

 and submits to none, whereas the one 

 lowest in rank has a strong habit for avoid- 

 ance and does no pecking. Those in inter- 

 mediate ranks show varying degrees of 

 both habits commensurate with social 

 status. Therefore, the frequency with which 

 individuals display dominance or submis- 

 siveness may be altered by subflocking 

 without disrupting the dominance relations 

 among the birds in the smaller groups 

 (Guhl, 1950). 



Of extreme importance in the method- 

 ology for studying aggressive behavior is 

 the control of what we will refer to as the 

 elements composing the substrate. The prob- 

 lem can be explained, Init it will l)e at some 

 length. 



V. Elements Comprising Substrate 



The study of animal behavior is beset 

 with problems of multifactorial relation- 

 ships. This produces either a perplexing 

 situation or an intriguing one, depending on 

 the viewpoint. It is virtually impossible to 

 control all of the known factors in a single 

 experiment, and some apparently minor ones 

 may gain in their influence when others are 

 controlled. There is a continual interaction 

 between the environment and the organism. 

 The experimenter is one of the factors. The 

 importance of this fact, which is also recog- 

 nized clinically (Matarozzo, Saslow, Mata- 

 rozzo and Phillips, 1958), has not always 

 been appreciated. The presence of the in- 

 vestigator, his mannerisms, and the methods 

 of handling the animals may alter behavior. 

 It must be recognized, too, that behavior 

 is the expression of an effort to adapt or to 

 adjust, and different conditions may lead 

 to different results. Animals are often main- 

 tained in one location and moved to an- 

 other for experimentation. Many animals 

 can adapt readily to such technicjues, but 

 the time required for adjustments should be 

 considered. In general, domestic species 

 adjust to laboratory conditions with less 

 diflficulty than do wild animals; Hediger 

 (1950) suggests that the confined environ- 



ment of wild animals requires certain fea- 

 tures of their natural environment. Other 

 parts of the substrate are the genie back- 

 ground, meteorologic conditions, and the 

 interaction of drives. All these factors will 

 be considered in the discussion of the in- 

 fluence of the endocrines on social behavior 

 which follows. 



A. HEREDITY AND LEVELS OF 

 AGGRESSIVE BEHAVIOR 



The wealth of information from com- 

 parative studies provides abundant evidence 

 that the genie background influences the 

 character of an animal's behavior. We will 

 mention only a few: phylogenetic studies 

 of social behavior patterns have been made 

 for orders of insects (Michener, 1953), ter- 

 mites (Emerson, 1938; Schmidt, 1955), bees 

 (Michener and Michener, 1951 ; Michener, 

 1953), fishes (Winn, 1958), and birds, e.g., 

 anis (Davis, 1942) and tits (Hinde, 1952). 

 The importance of the genie factor is also 

 apparent from observations of and experi- 

 ments with hybrids {e.g., finches, Hinde, 

 1956b j, from the existence of species dif- 

 ferences {e.g., fishes, Schlosberg, Duncan 

 and Daitch, 1949; Clark, Aronson and 

 Gordon, 1954) and breed differences (e.g., 

 dogs, Scott and Charles, 1953, 1954; chick- 

 ens. Potter, 1949; Hale, 1954; Allee and 

 Foreman, 1955). Scott (1954) discussed the 

 effects of selection and domestication on 

 various behavior patterns in the dog. In 

 genetically different stocks of male guinea 

 pigs, factors peculiar to the strains affected 

 the behavioral responses to testosterone 

 propionate (Riss, Valenstein, Sinks and 

 Young, 1955). Strain differences were also 

 found in the response of female guinea pigs 

 to estradiol and progesterone (Goy and 

 Young, 1957). Most of the studies cited 

 above were not concerned with agonistic 

 behavior per se, but it must be presumed 

 that strain differences would be as im- 

 portant for the display of agonistic behavior 

 as for all other social behavior including 

 reproductive behavior. 



Some breeds of domestic animals have 

 been developed by selection for particular 

 behavior patterns. Terriers among dogs, 

 gamecocks among chickens, and Siamese 

 fighting fish have a long, and largely un- 



