I’ve seen no evidence that these kinds of traits are inherently biological.
Regardless of the fact that we have significant evidence that these more “new” forms of masculinity that incorporate less domineering and aggressive mannerisms are beneficial to men, I simply haven’t seen any evidence that these traits are biological.
In the same way that when you don’t socialize a child to prefer certain clothes or toys, (or stigmatize against them) they generally just go with what they prefer in the moment along lines that don’t match the gender binary, from what I’ve seen, the same is generally true for behaviors. We’re heavily influenced by our cultures and by extension, our upbringing, to a degree that explains why these mannerisms are commonly expressed along gendered lines.
Interesting. I can’t seem to find anything on this study, but maybe that’s just my search engine not providing very relevant results.
What is a relevant result is the study from just a few years ago that Lego also commissioned, which they’re using to justify making their product lines more gender neutral, after finding that:
“girls today feel increasingly confident to engage in all types of play and creative activities, but remain held back by society’s ingrained gender stereotypes” and that “Girls […] are more open towards different types of creative play compared to what their parents and society typically encourage.”
And they found a significant effect from parents pushing their kids into certain interests and hobbies influencing the behaviors of children:
And they even showed that kids felt pressured not to engage in cross-gendered play, even when they wanted to:
Now, a quick note on your other point.
I don’t believe there is no difference at all between men and women. I simply believe that a lot of the things we say are inherent differences are actually not as inherent as people tend to believe.
For example, I’ve seen no evidence that women are inherently more kind/caring/empathetic than men in any biological way, only that society socializes them to be so, and thus we see that trend perpetuated over time. Yet if you ask most people, they’ll assume there’s something biological that makes women more like that emotionally.