'Who do you think made the first stone spear?" asks Temple Grandin. "That wasn't the yakkity yaks sitting around the campfire. It was some Asperger sitting in the back of a cave figuring out how to chip rocks into spearheads. Without some autistic traits you wouldn't even have a recording device to record this conversation on."

As many as one in 110 American children are affected by autism spectrum disorders, according to the Centers for Disease Control. Boys are four times more likely to be diagnosed than girls. But what...