Studied continuity and change in general cognitive ability from infancy to adolescence in adoptees (107 children), biological siblings (87 pairs), and twins (224 monozygotic and 189 dyzygotic pairs). Findings generally support previous findings about genetic and environmental factors, with the exception that in the transition to adolescence,…

Identifies three main strengths of Casey's spatial ability model, but notes that a study by McKeever found different results concerning the relationship between familial handedness and females' mental rotation ability. Considers the use of a familial handedness measure to be a weakness of the model because handedness might not be an inherited…

This article reviews positions of scientists, educators and publicists who resisted eugenics and determinism. The nature nurture controversy is discussed, as well as the impact of eugenics on American classrooms. Specific attention is given to four resisters: Dewey, Bagley, Jennings, and Lippmann. (IAH)

"The Bell Curve" declares that studies of separated identical twins--the "purest" of "direct" methods for estimating IQ heritability--indicate a value of +.75-+.80. But, the main study cited suggests a heritability of "two-thirds" for the middle class, and Herrnstein and Murray neglect to mention numerous…

The utility of developmental behavioral genetics in the study of reading disability is considered. Research which has found reading disability to be partly genetically determined is cited, and future research applications are discussed. (Author/JDD)

Biological determinism represents a pseudo-scientific inquiry that is ultimately used to foster a scientific rationale for the maintenance of classism, racism, and sexism in general. Genetic diversity is an inescapable fact, but it is cultures that human brains have created that most severely limit potential. (SLD)

The contentious nature-nurture debate in developmental psychology is poised to reach a rapprochement with contemporary concepts of gene-environment interaction, transaction, and fit. Discoveries over the past decade have revealed how neither genes nor the environment offers a sufficient window into human development. Rather, the most important…

Argues against testing for genetic differences between the races with respect to IQ, examines the views of Shockley, and extensively rebuts the writings of Jensen on this controversy. (BR)

Finds that the available data for the heretability of intelligence is inadequate to settle the question conclusively. Argues that the benefits of diversity can only be realized if equality of opportunity is complimented by equality of status. (EH)

This paper presents the results of a study which examined heritability ratios for the major ethnic and socioeconomic groups in the Los Angeles Unified School District. Scores on three measures (the Cooperative Primary Reading Test, the Comprehensive Test of Basic Skills, and a composite set of intelligence tests) were compared for twins from…

Milkman (TM 504 643) accuses Arthur Jensen of misapplying heritability data in speculating on the causes of racial differences in intelligence test scores, and offers a method for illuminating Jensen's alleged error. It is contended in this article that Milkman has misconstrued Jensen's argument and that his method is without point. (Author/CTM)

This article reviews sex studies of children of cousin marriages and three studies of children of incestuous matings. It is argued that these studies, taken as a whole, provide no substantial evidence for an inbreeding depression effect within the polygenic system commonly asserted to determine IQ. (Author/DB)

Conducted a trivariate genetic analysis of the Home Observation for Measurement of the Environment (HOME), Mental Development Index (MDI), and Task Orientation (TO). Found that for 101 nonadoptive and 92 adoptive sibling pairs at 12 and 24 months of age, TO explained the remaining genetic variance on the HOME not explained by the MDI. (MDM)

Criticizes claims in "The Bell Curve" that a high value for heritability of intelligence constrains the extent to which environmental changes can increase intelligence. Cites adoption studies and the increasing intelligence of successive cohorts of U.S. children as evidence that intelligence can increase substantially without heroic…

Posits that an evolutionary perspective can unite the study of the typical development for and individual variation within a species and that environments within the normal range for a species are required for species-normal development. Individual differences in children reared in normal environments arise primarily from genetic variation and…