Malcolm Gladwell calls those who accept the Mainstream Science on Intelligence statement "IQ fundamentalists", but the reality of g and the predictive validity of intelligence tests are widely accepted as consensus science by intelligence researchers, with some caveats. Reading Eurekalert and PhysOrg, I see press releases practically every day that analyze the correlation of intelligence with a variety of genetic and environmental factors. Here's one from yesterday:
Fit teenage boys are smarter
But muscle strength isn't the secret, study shows
In the first study to demonstrate a clear positive association between adolescent fitness and adult cognitive performance, Nancy Pedersen of the University of Southern California and colleagues in Sweden find that better cardiovascular health among teenage boys correlates to higher scores on a range of intelligence tests -- and more education and income later in life.
"During early adolescence and adulthood, the central nervous system displays considerable plasticity," said Pedersen, research professor of psychology at the USC College of Letters, Arts & Sciences. "Yet, the effect of exercise on cognition remains poorly understood."
Pedersen, lead author Maria Åberg of the University of Gothenburg and the research team looked at data for all 1.2 million Swedish men born between 1950 and 1976 who enlisted for mandatory military service at the age of 18.
In every measure of cognitive functioning they analyzed-- from verbal ability to logical performance to geometric perception to mechanical skills -- average test scores increased according to aerobic fitness.
However, scores on intelligence tests did not increase along with muscle strength, the researchers found.
"Positive associations with intelligence scores were restricted to cardiovascular fitness, not muscular strength," Pedersen explained, "supporting the notion that aerobic exercise improved cognition through the circulatory system influencing brain plasticity."
I support the consensus science on intelligence for the sake of promoting truth, but I also must admit that it especially concerns me that the modern denial of the reality of different intelligence levels will cause ethicists and the public to ignore the risks from human-equivalent artificial intelligence. After all, if all human beings are on the same general level of intelligence, plus or minus a few assorted strengths and weaknesses, then it becomes easy to deny that superintelligence is even theoretically possible.
Some people are just more intelligent than others in every possible way. (Though most people have strengths that others don't, such as through learning and talent.) This sounds unfair and politically incorrect, but that's what we see in the data. The modern neo-mystical pseudoscientific folk view of intelligence seems to indicate that if someone seems genuinely more intelligent at first, that intelligence must surely be accompanied by some major flaws, to "balance it out" on the cosmic scale. This may be true sometimes -- for instance, nerds tend to have poorer social skills than average -- but it doesn't always apply. Some people are just better at everything. This sort of talk is often considered forgivable when people mention it casually in real life in relation to a specific circumstance, but for some reason when it is put down in text in general terms, would-be egalitarians try to shoot holes in it with unscientific theories like Gardner's multiple intelligences concept.