What was the outcome of Beeman's (1947) study on castrated male mice?

• A. They displayed increased aggression
• B. They showed reduced aggression
• C. They became more passive
• D. Both B and C are correct

Answer: (D)

Beeman's study in 1947 on castrated male mice provided significant insights into the relationship between hormones and behavior, specifically regarding aggression. The key finding was that castration resulted in a reduction of aggressive behaviors in the male mice, demonstrating the influence of testosterone on aggression.

When male mice are castrated, their testosterone levels drop significantly, which correlates with a decrease in aggressive behavior. Alongside this, the mice also exhibited more passive behaviors as compared to their intact counterparts. The outcomes suggest that not only does the reduction of testosterone lead to lowered aggression, but it also promotes a more passive state in the animals.

This illustrates the broader principle in biological psychology that hormonal levels can profoundly affect behavior. The reduction in aggression and the increase in passivity confirm that castration leads to both diminished aggressive tendencies and a shift towards less active, passive behaviors. Consequently, the correct selection of both reduced aggression and increased passivity encapsulates the findings of Beeman's study effectively.