Why does testosterone make men aggressive?

Testosterone: Is what makes males display male behaviour and aggression is one of those behaviours. Of course aggression is in the eye of the beholder. If a male is protecting his mate and children from attack, is that aggression or is it defending your family? Another role for testosterone is allow the most fit males to mate most successfully, as is required for evolutionary selection of the best traits.

It can: It is one of the male hormones that is associated with aggressive behavior if one has too much, but usually not normally. Over aggressive behavior is often a sign of something wrong inside a person and a counselor can often help to sort it out if the doc knows hormone levels are fine.

Testosterone: Only if you get it somewhere without a prescription. Your doctor should test your testosterone level and see if your level is low (needs replacement) or not. Not a tough test.