Considerations Relating to the Study of Group Differences in Intelligence

ABSTRACT— There are signs that the debate over racial and gender differences in intelligence is about to begin again. In this article we will be concerned primarily with racial differences but will make remarks about gender differences where applicable. Previously there have been bitter arguments over whether or not races exist, over whether it is either important or proper to study racial and gender differences in intelligence, and over the conclusions that have been drawn about environmental and genetic causes as determinants of these differences. We argue that races do, indeed, exist and that studying differences in cognitive competence between groups is a reasonable thing to do. We also point out that past research on both racial and gender differences in intelligence has been marked by methodological errors and overgeneralizations by researchers on all sides of the issue. We propose ten principles of design, analysis, and reporting that ought to be considered carefully when doing or evaluating research in this area.     

The status of the concept of intelligence

Psychometric studies have shown that “general intelligence” should be broken down into the ability to apply learned solutions to new problems (crystallized intelligence) and the ability to deal with novel intellectual problems (fluid intelligence). This distinction has been amplified upon by studies of individual differences in information processing. Crystallized intelligence depends on the problem-solving schema that people have acquired and upon their efficiency in accessing information in long-term memory. Fluid intelligence is associated with the ability to access and manage relatively large amounts of information in working memory. Measures of fluid and crystallized intelligence are important predictors of objectively measured workplace performance. Studies of actual and simulated workplaces have shown that this is largely due to differences in people's ability to manage information and the speed with which the details of a job can be grasped.