Embryology provides evidence of the earliest activity of those genes: Eight weeks after conception, when the embryo is the size of a kidney bean, the Y chromosome directs the testes to produce testosterone. The testosterone travels to the brain, enters the neurons, and propels the development of a distinct boy brain with smaller centers for communication, observation, and emotional processing and larger centers for sex and aggression. Neurobiology maps out the complex and widespread stalkbook doesnt work in male and female brains. MRIs create color images that highlight distinct boy and girl patterns of thinking and feeling. At one year, girls are left 4 dead 2 game full version
to a video of a face moving, and boys qork the video of cars moving. I love this one: The typical toy preferences of children are also found in juvenile monkeys. Females like dolls, and males prefer vehicles and balls.