Wall Street Journal, January 18, 2007.
If “intellectually gifted” is defined to mean people who can become theoretical physicists, then we’re talking about no more than a few people per thousand and perhaps many fewer. They are cognitive curiosities, too rare to have that much impact on the functioning of society from day to day. But if “intellectually gifted” is defined to mean people who can stand out in almost any profession short of theoretical physics, then research about IQ and job performance indicates that an IQ of at least 120 is usually needed. That number demarcates the top 10% of the IQ distribution, or about 15 million people in today’s labor force — a lot of people.
In professions screened for IQ by educational requirements — medicine, engineering, law, the sciences and academia — the great majority of people must, by the nature of the selection process, have IQs over 120. Evidence about who enters occupations where the screening is not directly linked to IQ indicates that people with IQs of 120 or higher also occupy large proportions of positions in the upper reaches of corporate America and the senior ranks of government. People in the top 10% of intelligence produce most of the books and newspaper articles we read and the television programs and movies we watch. They are the people in the laboratories and at workstations who invent our new pharmaceuticals, computer chips, software and every other form of advanced technology.