The article I linked was exactly evidence of that kind. Maybe you can comment on it.
Thank you Reelya, that is indeed such an article.
However, I don't understand where, if at all, they controlled for the confound of other children or adults coercing or influencing a certain type of play BECAUSE of physical differences brought on by testosterone differences.
It certainly does show a correlation hormones <--> gender role behavior. But not necessarily a directional hormones --> gender role behavior, as far as I can tell? (they might only be TRYING to show a correlation, some studies only attempt to do that).
They mention controlling these factors:
Gestational age at amniocentesis, maternal age, maternal education, and child’s age at PSAI assessment were included for control purposes.
The first and last are just to screen out preemies, the next two presumably an attempt to get roughly controlled culture and parenting types.
But making sure your parents have similar parenting types does not ensure that the parenting style they all have is not one of "encourage kids into our pre-existing gender role assumptions"
Note:
IF they could establish that parents were unable to even intuitively distinguish children of varying testosterone levels, then this paper would become much more interesting. But parents might be able to. Perhaps more amniotic testosterone leads to faster muscle development or something like that, and so they kick a little bit more or whatnot, and parents go "oh look at them! Gonna be such a soccer player" blah blah... so it begins, before you're even born.