Comic Strips

It would make sense. There are other behaviours that directly lower male aggression. Smiling and emotional tears.

Which is awesome for babies since non-human primate males are known to kill offspring of other males in order to get the mother in estrus sooner.

It's also the reason women smile when nervous and cry a lot more. I suppose you have to if you lack offense and defence. E.g. estrogens slowing muscular and skeletal growth in the upper body. And growing hair enough for thermal regulation, but not enough to redistribute blunt forces. The reason beards exist is to protect the jaw.

Interestingly, the main motive for men to commit homicide is dominance seeking behaviour. Men are more likely to kill every age with exception of infants. Women's main motives for homicide are self-defence first and jelousy second. Infanticide is almost exclusively done by women. Often their own too. Never trust a woman who had a miscarriage with your newborn or your pregnant wife. High prolactin, loss of child and stealing babies is not just a human thing.

I wonder how the willingness to kill your own (high risk and expensive) baby influenced human evolution. Since it's the other way around in other primates. Recon it reduced rape to be merely a dominance thing rather than a reproductive strategy?