Recently, Caroline Walls has written a very interesting piece in the British Journal of Psychology, in which she discusses nationality and aging. While it is true that some factors, like race, are beyond our control, many aspects of personality do impact our ability to be competitive or work productively, but one of the biggest influences on how we age is our nationality. In particular, her study reveals that those with a European parent tend to be less successful as adults, even if they have similar educational and career achievements.
The results were striking because the results of her tests showed that those who had a European parent were much more likely to be less able to race after age 60, with the effect becoming stronger for those with a European parent by the time they reached middle age. It turned out that even a relatively small number of the test subjects (Netherlands v. England) demonstrated significant race differences in their ability to race later on in adulthood, with the largest differences being observed between children with German parents and those with English parents. This research demonstrates a very important point: that the results of studies based on race are often highly unanticipated and vary significantly from what is found when comparing siblings. In this case, the results were replicated across several different race/ethnicity comparisons, but the effect sizes were different, with the outcome being that, when it came to youritability of intelligence, your nationality has a lot to do with the level of intelligence you inherit and your success as an adult.
Her next piece of research is very interesting and sheds even more light on the question of how nationality relates to youritability of intelligence. In this study, she compares sibling differences in IQ, and her results are quite interesting. The results show that identical twins, who share exactly the same genes, have very similar IQ scores; whereas non-identical twins differ by a large amount, which essentially means that they have very different genes. The results imply that genetics heavily influences the nature of the individual’s IQ, whereas the environment is largely determined by heredity.