No research or evolutionary hoo-ha needed.
Its simple.
This is your corn hole.
This is your money hole.
Don’t get them mixed them up, no matter what.
LOL about the holes. Reminds me how activists for “transgendered” have said we are too focused on crotches, and we should talk of the “front hole” rather the actual body parts in that area of the anatomy.
It is called animal dimorphism, common in apes etc.
Where the male is statistically larger than the female.
It is just nature. can’t fight it, can’t argue about it.