Spinoff of this ongoing thread on race-and-intelligence. Your IQ (assuming it measures anything important/meaningful at all – see the controversy between the assumption of a general intelligence factor and Howard Gardner’s theory of multiple intelligences) is not the only important thing about your mind, is it? People used to have all kinds of perceptions of “racial” or even “national” characteristics of personality and temperament, all presumed to be “in the blood.” E.g., swap an Irish baby and an English baby in the cradle, and the Irish baby, raised by English parents, nevertheless will grow up to be a temperamentally violent, hard-drinking, hot-headed poet; the English baby raised by Irish parents will grow up to be a cold-blooded, rigorously honest prig; each astonishing peers and parents. Such hereditary characteristics used to be popularly attributed even to social classes or family lines – and still are, perhaps, see the baby-switching plot in Big Business, 1988.
Have any of these assumptions or stereotypes ever been subjected to scientific scrutiny, using psychometric instruments other than IQ tests? I.e., is there any known differential in racial or ethnic groups, however defined, in Myers-Briggs Personality Type or emotional intelligence or anything else (believed by some psychologists to be) measurable? And, if so, has anyone tried to tease out the environmental from the hereditary factors causing such differences?