An important feature of social aggression that distinguishes it from other forms of aggression in many mammalian species is that it is

I believe the answer is: dependent on testosterone

Testosterone played a role in increasing a mammals' tendency to display dominance toward another mammals.
Increasing testosterone often caused higher tendency to displayed aggressive behaviors, which is why the number of males of arrested for aggressive violence in human society far outnumbered the females.

Hamlet's fourth soliloquy is probably his most famous one - "to be or not to be."it is rather different from his previous soliloquies because now he is contemplating something that didn't come up before - suicide. he is thinking whether it is worth it to fight to find his father's murderer when in the end all of them are going to die, so why not die sooner than later. he is contemplating if he should go on fighting or just kill himself and end it all, which is why this soliloquy in particular is rather depressing, hesitant, and gives a deeper insight into hamlet's madness.