Competitive behavior in male, female, and pseudohermaphroditic female dogs.

Male, spayed female, and pseudohermaphroditic female dogs were tested in pairs for competition over a large bone. Pseudohermaphroditic females had been exposed to testosterone proprionate before and immediately after birth. Two types of tests were used. In equal opportunity tests (EO tests), both members of a pair had equal chance to seize the bone when it was tossed into the arena. Each EO test was followed by an established possession test (EP test). During an EP test, the loser of the preceding EO test was given possession of the bone before the former winner was returned to the test arena. Every dog was tested against all other members of its own and both of the other groups. Males won 78 of 100 EO tests against normal females but only 61 of 100 against pseudohermaphroditic females. Pseudohermaphroditic females won 70 of 100 EO tests against normal females. When either normal or pseudohermaphroditic females were given possession of the bone in EP tests they were equally ineffective in defense against male challengers, losing 75% and 71% of their tests, respectively. Both types of females were much more successful in defending possession during EP tests against each other than they had been against males. When normal and pseudohermaphroditic females were treated with testosterone propionate, their performance in competition tests was not altered. Androgenic stimulation before and immediately after birth permanently modified the social behavior of pseudohermaphroditic females as well as the behavior of males and normal females toward the experimental dogs. However, the changes could not appropriately be described as "masculinization." Developmentally androgenized females differed from members of their own sex, but they differed just as greatly from normal males.