I have argued that the identification of a casual and biological link between personality and behaviour has ramifications for society. I have also noted how difficult it is for people to deal with any degree of determinism in the psychological sciences.

As most I/O Psychologists know, cognitive ability is one of the most researched and valid predictors of job performance. The average correlation coefficient for cognitive ability and job performance is in the area of 0.5-0.6 (e.g. Schmidt and Hunter, 1998). This is supported in a more recent British journal, the abstract of which is quoted below:

Bertua, C., Anderson, N., and Salgado, J.F. (2005 – September) The predictive validity of cognitive ability tests: A UK meta-analysis. Journal of Occupational and Organizational Psychology, 78(3), pp. 387-410.


A meta-analysis on the validity of tests of general mental ability (GMA) and specific cognitive abilities for predicting job performance and training success in the UK was conducted. An extensive literature search resulted in a database of 283 independent samples with job performance as the criterion (N = 13,262), and 223 with training success as the criterion (N = 75,311). Primary studies were also coded by occupational group, resulting in seven main groups (clerical, engineer, professional, driver, operator, manager, and sales), and by type of specific ability test (verbal, numerical, perceptual, and spatial). Results indicate that GMA and specific ability tests are valid predictors of both job performance and training success, with operational validities in the magnitude of 0 .5-0.6. Minor differences between these UK findings and previous US meta-analyses are reported. As expected, operational validities were moderated by occupational group, with occupational families possessing greater job complexity demonstrating higher operational validities between cognitive tests and job performance and training success. Implications for the practical use of tests of GMA and specific cognitive abilities in the context of UK selection practices are discussed in the conclusion.

How much of this ability is genetic, I would not know. This question interests me less than the question of how you help people to obtain a performance level to the best of their ability. The brain is very malleable and despite limitations set by genetics, the variation for performance inside those limitations is huge.

The fact remains that discussing pre-determined cognitive ability as a societal limitation is a very dangerous area to tread. Many famous careers have been ruined, or at least maligned, by getting into this debate. Many psychologists have had their ethics questioned for even asking the question. Perhaps none quite as public in recent times as the outcry against Nobel-prize winner James Watson. Here is an article from the Independent as a reminder to those who may forget that cognitive determinism, even the mention of which is an area that is socially very charged and illustrative of the problems of any degree of determinism for Psychology should it exist.

Anger at scientist’s ‘whites more intelligent than blacks’ comment, Thursday, October 18, 2007, By Cahal Milmo

“One of the world’s most eminent scientists was embroiled in an extraordinary row last night after he claimed that black people were less intelligent than white people and the idea that “equal powers of reason” were shared across racial groups was a delusion. James Watson, a Nobel Prize winner for his part in the unravelling of DNA who now runs one of America’s leading scientific research institutions, drew widespread condemnation for comments he made before his arrival in Britain for a speaking tour at venues including the Science Museum in London”.

Read the full article