The essay integrates the psychometric intelligence approach with the cognitive-developmental approach or the stage theory erected by Piaget and his disciples. The latter led to Piagetian Cross-Cultural Psychology and the accumulation of an immense body of data. It shows that different IQ levels are indicative of the peculiar stages of cognitive…

In longitudinal studies data is collected in a series of waves. Each wave after the first suffers from attrition. Therefore it can be difficult to discriminate between changes in sample parameters due to a longitudinal process (e.g. ageing) and changes due to attrition. The problem is particularly vexing if one of the purposes is to compare…

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

Proposes a developmental theory of sex differences in intelligence that states that the faster maturation and brain size growth in girls up to age 15 compensates for their smaller brain size so that sex differences in intelligence are very small. Discusses evidence that supports this theory. (SLD)

The president of the Pioneer Fund, a nonprofit foundation that makes grants into studies of individual and racial differences, addresses some of the media attacks on the fund in the context of the nature-nurture controversy. (SLD)

Sex differences on the WISC-R (Wechsler Intelligence Scale for Children-Revised) are examined in a sample of 1258 11 year olds in Mauritius. Boys obtained a significantly higher Full Scale IQ by 5.8 IQ points. Boys obtained a higher Performance IQ by 6.5 IQ points and a higher Verbal IQ by 1.0 IQ points. On the subtests, girls obtained a…

Describes some of the ways conformity in science is rewarded and defiance punished with reference to the work of Arthur Jensen. Notes that some of his work makes outstanding contributions to the science of intelligence, while other work is considered regressive. (SLD)

Describes public controversy over Jensen's work on genetic differences in intelligence as an example of sociopolitical consequences that can accompany the dispersion in "g" (general factor of intelligence) in a society. (Author/SLD)

Focuses on the integrity and ethics of Arthur Jensen, while tracing the negative reactions his work on genetic differences in intelligence has evoked. Outlines some other areas in which Jensen has worked and commends his emphasis on honest psychological science. (SLD)

In addition to establishing the relationship between reaction time (RT) and intelligence, Jensen has explored the role of intraindividual variability and its genetic basis. Jensen's theories blend facts from behavioral research on RT with neurological events. (Author/SLD)

Considers the contribution to information-processing accounts of human intelligence differences made by Arthur Jensen, commending his persistence in research and noting his reductionist orientation. Explores the question of correlated vectors studied by Jensen. (SLD)