Denise Berg, a professor of psychology, and her molecular biologist husband, Gabe, expected an intelligent child. When Denise gave birth to Zack, they were thrilled. They were not surprised to find that Zack had physical and mental gifts, but were astounded by their magnitude. By every parameter, Zack was extraordinarily gifted and they took pride in their genes and in their good fortune.What they didn't know was that Zack's gifts were the result...