Re: No, it's Nature.

Look at the pic. The hairstyles are different but there is enough visibility that you can tell the heads, necks and shoulders.

There certainly are borderline cases. Especially in Thailand. But it's different conceding 1 or 2 each way out of 30, and the patently absurd statement often proferred that they are just the same and indistinguishable barring cultural markers or visible genitalia. That is just false. The minority of exceptions remain a minority, while the majority is clearly feminine or masculine. The lack of bewbs or wide hips having correlates in the lack of wide shoulders or thick body hair.

And I say this as someone who actively prefers short hair in girls.