In this article, it is argued that it makes sense to define and distinguish three levels of human intelligence: intelligence as genotypical potential, intelligence as actualised in environmental interaction, and intelligence as measured by tests (IQ). This raises the questions of what is meant by the term "intelligence as potential", and…

Crude and dangerous ideas about the genetic heritability of intelligence, and a supposed biological basis for the Black/White achievement gap, are alive and well inside the education policy process but taking new and more subtle forms. Drawing on Critical Race Theory, the paper analyses recent hereditarian writing, in the UK and the USA, and…

In this paper we assess the presence of assortative mating, gene-environment interaction and the heritability of intelligence in childhood using a twin family design with twins, their siblings and parents from 112 families. We evaluate two competing hypotheses about the cause of assortative mating in intelligence: social homogamy and phenotypic…

Studies by the late English psychologist Cyril Burt of IQ scores of separated twins strongly suggested that intelligence was inherited. A summary of recent research costs doubt upon the validity of Burt's work. (SL)

Presents arguments for the case that Burt did fake his results. (IRT)

Argues that Burt did not fake his results. (IRT)

Four basic assumptions of IQ tests - age constancy, scholastic validity, standard environment and performance suggiciency are alien to Piaget's theory. Heredity cannot be statistically separated from environment; therefore, Piagetian theory would suggest the nature-nurture controversy is devoid of meaning. (ST)

The principal author of Inequality: A Reassessment of the Effects of Family and Schooling in America (1972) comments on three reviews of the book. For related articles see TM 501 196-199. (MLP)

Examines recent developments in the American debate over heredity and environment. (RM)

Correlations on subscales of Wechsler intelligence quotient tests and the Revised Beta Examination were obtained for biologically related and unrelated individuals in 181 adoptive families in the Texas Adoption Project. Generally higher correlations for biologically related individuals support the importance of genetic influence in intellectual…

Research has shown that differences among ordinary people in intelligence and personality depend equally on individual genetic variability and on differences in the environments that siblings experience within the same family, not differences in the neighborhood, school, and community environments. As of yet, there are no adequate theories to…

The estimation of genetic models reported by J. L. Jinks and L. J. Eaves in a recent review are critically examined. A number of errors in procedure and interpretation are found. It is concluded that the evidence, provided by kinship correlations, for the proposition that intelligence is highly heritable, is not persuasive. (Author/BJG)

This paper reviews what is known about intelligence and the use of intelligence tests. Environmental and hereditary factors that affect performance on intelligence tests are reviewed, along with various theories that have been proposed about the basis of intelligence. Intelligence tests do not test intelligence per se but make inferences about a…

The portions of Inequality: A Reassessment of the Effect of Family and Schooling in America (Jencks, et al 1972) concerned with inequality in cognitive skills and estimating the heritability of IQ scores are reviewed. For related articles see TM 501 196-200. (MLP)

The purpose of this paper is to clarify some of the conceptual issues involved in discussions of psychology and education which rely on the assumption that biological factors serve as a basis or are responsible for human intelligence. (Author/ND)