[marchenko]

Evopsych explanations can often be used to argue both sides of any issue. For example, T is implicated in male aggression, which is useful when fending off predators both animal and human, but dangerous when you have a helpless, often extremely irritating Bundle of Evolutionary Fitness around. T is also thought to be involved in mate-seeking behaviour, which one may wish to downregulate for a while after successfully reproducing in order to devote resources to infant survival. Testosterone is also metabolically expensive, and those costs may be paid at the expense of the immune system. It might be advantageous to upregulate immune functions when an immuno-compromised neonate is around. You and the author could both be correct, but neglect important components of the testosterone fitness package.