nearly twothirds of the women 37 of the 59 were found to have traces of the male y chromosome in multiple regions of sons dna shows up in moms brain new findings reveal as a child i was always mystified by those girls who always wanted to play mommy or house it just never held the same allure to me sure i liked barbies but i was pretending they were flying around the world or solving mysteries not having babies or getting married to ken discovery of mom gene may explain why some of us dont crave having kids