The New York Times:
People who do well on a test of one mental ability — let’s say a test of verbal ability — will tend to do well on tests of others — math ability, spatial ability, and so on. This finding, which has been replicated thousands of times, implies that there is a general factor of human intelligence. Psychologists call this factor “g.” We still don’t know what underlies g. Ian Deary, a researcher at the University of Edinburgh, has argued that the speed of perceptual processes is one piece of the puzzle, while Randall Engle, of the Georgia Institute of Technology, has established that intelligence is strongly linked to working memory capacity, which he thinks of as the ability to hold information in the focus of attention. Others suggest that when we try to boil down the human intellect to a single factor, we lose view of its complexity.
What we do know is that measures of general intelligence are practically useful. Frank Schmidt, of the University of Iowa, and the late John Hunter, of Michigan State University, documented that g is the single best predictor of job performance across a wide range of occupations — better than personality, interest, motivation and even job experience. People who do well on tests of intelligence tend to make the best mechanics, managers, clerks, salespeople, pilots, detectives and scientists. They also tend to make the best teachers. It makes perfectly good sense, as Andrew Biggs and Jason Richwine argue, to use intelligence as a predictor of teacher performance. We should want smart people to be our teachers.
Read the whole story: The New York Times