[llamaimperative]

Why couldn’t it just be cognitive? Your endocrine system is not totally isolated from your cognition.

It’s fairly apparent how fathers amped up on testosterone could be worse for offspring survival than those who have a drop, so the evolutionary pressure is pretty clear, then the mechanism is readily explained by “they know that they have a child.”

How does adrenaline get released when you see a dangerous situation with merely your eyeballs?