Scientists in North Carolina say they have identified a gene that affects IQ, a finding that, if confirmed, would be a significant step toward understanding the genetic basis for intelligence. The new research could also have ethical implications because the effect of the gene appears to be quite dramatic: The scientists say that males who inherit a particular version of the gene have, on average, an IQ that is 20 points lower than males who don't. "I have to admit, the ramifications of it are great," said Randy Jirtle, the Duke University biologist who led the new research, noting that...