This makes some sense, but your analysis assumes that observed parental gender roles aren’t responsible for the patterning you describe before 1yr. I’d be more convinced of an analysis of child rearing in a “gender neutral environment” created by those who do not have the gender they were assigned at birth. Do these patterns still occur? I’d be more inclined to buy a biological explanation then, but without that, all you’re telling me is that a 10mo baby is extremely adept at absorbing patterns from their parents.