Castration, androgens, and dominance status in the rat

The effects of castration and androgen replacement on dominance status were studied in 22 male rats by the method of paired competitive encounters. The dominance hierarchy existing before castration became disrupted after castration. It was reinstated by daily doses of 1 µ gm testosterone proprionate; a higher daily dose of 50 µ gm increased further the correlation between the initial hierarchy and the post-replacement hierarchy. It is suggested that the differential effects of identical amounts of androgens on dominance status arise from individual differences in the complexity and development of the neural structures involved in aggressive behavior.