I have thought about this a lot, and yet when you observe little kids, little boys want to play with trucks and cars, and little girls like playing with dolls. Nobody has to tell boys to play with cars or toy guns. They just like them. Obviously everybody's an individual. But by and large I think there are trends at such a young age it's apparent that the gender differences in occupational choices aren't just due to culture.

Your big assumption here is that kids are ignorant of culture and pay no attention to non-explicit signals. This is demonstrably and wholly false.

"In experiments, male adolescent monkeys also prefer to play with wheeled vehicles while the females prefer dolls — and their societies say nothing on the matter."

https://www.google.com/amp/s/amp.livescience.com/22677-girls...

This suggests there may be something deeper than expectation from culture and society.

Monkeys don't have language and culture.

This study suggests nothing about the impact of culture and society on human individuals.

Isn't that the point? Monkeys don't have language and culture, but males and females still prefer different types of things, giving evidence to the argument that it is not simply culture influencing children's toy preferences

This is a study about monkeys. How does this and why should this apply to humans?

Because we both evolved from a distant ancestor, any behavior we share is very likely to be an evolutionary trait.

I think that boys just plain will prefer the cars over the doll if you give them the choice, regardless of culture. The story of David Reimer is instructive. The boy at 22 months had a botched circumcision. So the doctors just chopped off his balls and made a vagina for him. He had a horrible time becoming a "girl" and as soon as he was told he was a boy as a teen immediately reverted and lived the rest of his life as a boy as much as he could. The reason his parents told him anyways was because he threatened to take his own life, hating to see the therapist who was trying to make him act like a girl.

https://en.m.wikipedia.org/wiki/David_Reimer

And what about biological males who would rather dress and act like the women in their society?

How does this anecdote prove that it was biology and not the same kind of transgendered cultural preferences?

Born an uncultured male, raised an American boy, prefers life as an American woman.

Born an uncultured male, raised an American girl, prefers life as an American man.

As far as I can tell this only shows that adult gender expressions have very little to do with biology or childhood.

Are babies born gay? You might as well be asking if babies are born doctors or poets!

Little boys and girls also don't want to eat their vegetables or pick up their toys.

What do babies have to do with socialized adult behavior?

I'm not saying that biology has no impact on behavior, I'm saying that it barely has any impact when compared to the influence of language and culture.

Well the research says you are wrong. This is not exactly exiting bed time reading but shows my point.

https://www.researchgate.net/publication/38061313_Men_and_Th...

Actually, you've shown nothing. No-one's denying these differences exist. The question's whether they're mutable. And gender expression is clearly mutable, you just need to visit an old art gallery to see that.