Attractivity of male and female rats after early endocrine manipulation

Approach behavior toward males and approach behavior toward females were studied in the male rat. Adult male rats approached neonatally castrated male rats more than they approached intact males. Neonatally androgenized female rats and estrous female rats were equally approached. A preferential approach toward the androgenized female was evident when the alternative incentive was a proestrous female. These adult patterns of approach behavior appeared on Day 50 after birth. It is concluded that early endocrine manipulation influences the attractivity of the incentives.