A 2002 study further examined the impact of non-IQ factors on income and concluded that an individual's location, inherited wealth, race, and schooling are more important as factors in determining income than IQ.
En undersøgelse fra 2002 undersøgte yderligere virkningen af andre faktorer på indkomst end IQ og konkluderede, at en persons placering, arvet rigdom, race, og skolegang er vigtigere som faktorer til determinering af indkomst end IQ.