Individual Differences

[H]ow should we prepare for the likelihood that in the coming years, genetic studies will show that behavioral or cognitive traits are influenced by genetic variation, and that these traits will differ on average cross human populations, both with regard to their average and their variation within populations? Even if we do not yet know what those differences will be, we need to come up with a new way of thinking that can accommodate such differences, rather than deny categorically that differences can exist and so find ourselves caught without a strategy once they are found.

It would be tempting, in the wake of the genome revolution, to settle on a new comforting platitude, invoking the history of repeated admixture in the human past as an argument for population differences being meaningless. But such a statement is wrongheaded, as if we were to randomly pick two people living in the world today, we would find that many of the population lineages contributing to them have been isolated from each other for long enough that there has been ample opportunity for substantial average biological differences to arise between them. The right way to deal with the inevitable discovery of substantial differences across populations is to realize that their existence should not affect the way we conduct ourselves. As a society we should commit to according everyone equal rights despite the differences that exist among individuals. If we aspire to treat all individuals with respect regardless of the extraordinary differences that exist among individuals within a population, it should not be so much more of an effort to accommodate the smaller but still significant average differences across populations.

K. Helmut Reich, How could we get to a more peaceful and sustainable human world society? The role of science and religion, Zygon, vol. 47, no. 2, 2012, p. 265

Continued research with the tools of genetic epidemiology, population genetics, psychometrics, and cognitive neuroscience is likely to settle many of the contentious issues raised in Nisbett’s book, even without a centralized effort toward any such narrow goal. Given that much of the critical research so clearly lies ahead, Nisbett’s certainty regarding his own premature conclusions is quite remarkable. Some of this may be owed to the disturbing possibilities raised by the alternatives. Even the prospect that current group differences might be eliminated by a combination of biological enhancement and environmental improvement will fail to put all observers at ease, since the prospect of biologically based remedies is itself frightening to many. For what it is worth, I believe that the possibilities regarding both the state of nature and our powers of control should leave us reasonably optimistic about what the future might hold. But I confess to less than total confidence in even this qualified remark, and I envy Nisbett his certitude.

James J. Lee, Review of Richard Nisbett, Intelligence and How to Get It, Personality and Individual Differences, vol. 48, no. 2, 2010, pp. 247–255, p. 254

The idea that women and men might actually think differently, that is have different preferred modes of thinking or different thinking abilities, came up in both classes. At the time, it seemed clear to me that any between-sex differences in thinking abilities were due to socialization practices, artifacts and mistakes in the research, and bias and prejudice. After reviewing a pile of journal articles that stood several feet high and numerous books and book chapters that dwarfed the stack of journal articles, I changed my mind. The task I had undertaken certainly wasn’t simple and the conclusions that I had expected to make had to be revised.

The literature on sex differences in cognitive abilities is filled with inconsistent findings, contradictory theories, and emotional claims that are unsupported by the research. Yet, despite all of the noise in the data, clear and consistent messages could be heard. There are real, and in some cases sizable, sex differences with respect to some cognitive abilities. Socialization practices are undoubtedly important, but there is also good evidence that biological sex differences play a role in establishing and maintaining cognitive sex differences, a conclusion that I wasn’t prepared to make when I began reviewing the relevant literature.

Diane F. Halpern, Sex differences in cognitive abilities, New York, 2012, p. xxi