But there are some norms since food supply levels have been steady.
But there are many who exist outside of the norm.
Some things have just always been consistent:
1) Waist to hip ratio
Again, it is individual. There are men who find absolute beauty in the Dolly Parton's of this world (big boobs and smaller hips) and others who find it ugly. Beauty is individual.
2) Clear eyes, good skin, good teeth
3) Proportions
Also considered when buying a horse.
There's a universal standard of beauty with a real biological basis. There will always be deviations, but it's there. People who fit that have a very real advantage. Babies respond more positively to people who are considered "attractive" in a mainstream way. We're programmed to feel a certain way about people because of how they look.
Are we?
So because I don't find Brad Pitt to be beautiful, I am somehow programmed wrong?
As for babies.. again, subjective. I have a friend who is drop dead gorgeous and modeled her way through law school. Stunning would be the word that many use to describe her. Yet when my youngest was a baby, he would scream in horror and terror each time she came near him. And I have a friend who is obese, what many would consider to be ugly and my son adored and would actually lunge to be held by him. She would be considered attractive in a "mainstream way" and he would never be considered so.
We are programmed to feel a response to people who are attracted to us, as individuals. Some people, the greater majority in fact, are sheep and will only find beauty in others because they are told that is what is beautiful. Kind of like the people who simply must have the latest in fashion, regardless of whether it is beautiful or not (I bring to mind the bubble skirt of the 80's and leg warmers worn with said bubble skirt),
because they are told it is beautiful. Then when they look back, they ask themselves "what in the hell was I thinking"..