[AnnieBL]

When considering environmental factors, remember that it is necessary to consider not only what you yourself may have been exposed to, but also what your mother may have been exposed to during her pregnancy with you (and also with your sibling). I don't know your age, but is it possible that she was treated with DES during pregnancy? It was for a long time (as far as I can recollect about 25 years from 1939) very widely administered in the mistaken belief that it guarded against miscarriage, particularly to women who had already had a miscarriage, and being a powerful synthetic estrogen it definitely could and some times did disrupt normal gender conditioning of the fetal brain. I think that there are estimated to have been an eight figure number of DES kids in the US alone, and most are quite unaware of the fact. I'm not certain that this counts as either nature or nurture.