In part two. Gendered behavior affinity is biologically imprinted. I read the evidence.
I find the Hines study very convincing. In essence nature provided a double-blind case study of the effects of masculinization on girl play behavior.
Because of the natural control group, the influence of culture has been controlled for in an experiment. I believe that Hines et al. have proven the biological basis for male-typical play behaviors being biological and caused by fetal androgens. These behaviors are the biological basis for gender variance.
keywords: feminism, mtf, ftm, brainscience, hormones, transgender, intersex, toys, play, boys, girls, androgens, hines, zucker, miltondiamond