' Smart DNA ' could explain IQ is inherited IN THE ANGRY DEBATE over how much of IQ comes from the genes that children inherit from parents and how much comes from experirnces, one little fact gets overlooked: no one has identified any genes ( other than those that cause retardation) that affect intelligence. So researchers loed by Robert Plomin of London's institute of Psychiatry decided to look for some. They figured that if you want to find a " smart gene, " you should look in smart kids. They therefore examine the DNA of students like those who are so bright they take college entrance exams four years early- and still score at Princeton-cal-iber levels. The scientists found what they soudgt. " We have ," says Plomin, "the first specific gene ever associated with general intelligence, " Plomin's colleagues drew blood from two groups of 51 children each, all 6 to 15 years old and living in six counties around Cleveland. In one group,...