Depends where in the world you are. In the US it was popularized by Dr Kellogg to curb masturbation. He also recommended a few drops of carbolic acid applied to young girls clits to damage the nerves and avoid what he called "abnormal excitement".

Dude was opposed to pretty much anything even vaguely resembling pleasure, he invented corn flakes as a food to be as bland and tasteless as possible. The only reason they ever became a popular breakfast cereal is because of his brother adding sugar to them despite Kelloggs objections

'cleanliness' and 'looking like their father' were later justifications after the practice had already gained traction.

This is so screwed, too.

Like, I was once tasked to explain to my nephew how to properly clean a penis at, like, age of 7. C'mon, parents, what are you there for?!

Just literally teach it alongside cleaning every other body part, what's the issue? Why should another man show this in particular to your kid?

This doesn't make it justifiable, but circumcision goes back a lot longer than our culture has existed. If Judaism had won out instead of Christianity, it could have been even more widespread than it is now. Some Muslim sects also mandate circumcision, and they could be the ones ruling the world.

Unfortunately, circumcision is a particular form of mutilation that transcends cultures.

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?

I am male and I did like sniffing my baby's head. Interesting.

Nah, it was rather in a context of how cute and nice-smelling babies are, not that it was an immediate new discovery

TIL but I don't know if I'm happy about it

Thanks for the share though!