Originally prepared by: Jonathan Plucker (Fall 2002)
Originally prepared by: Jonathan Plucker (Fall 2002)
The American Psychological Association (APA) Task Force on Intelligence was created in response to the debate surrounding the publication of The Bell Curve in 1994. The task force issued its report in 1995 and published a revised version in the February 1996 issue of American Psychologist. The report and article have been influential and are highly cited. In this Hot Topic, we refer to the group as the 1996 task force because the 1996 article drew the most attention to the group’s work.
Why an APA Task Force?
The publication of The Bell Curve in the fall of 1994 generated a tremendous amount of controversy, both in the scientific community and the mass media. The APA Board of Scientific Affairs, during a discussion of the controversy in late fall 1994, concluded that much of the public debate was ill-informed, overly political, and not constructive. As a result, the board established the task force on intelligence to identify, examine and summarize relevant research on intelligence.
Members of the Task Force
The members of the task force were chosen during a detailed process. Dr. Ulric Neisser, professor of psychology at Emory University, was appointed chair of the task force, several other members were nominated by one of several APA constituencies, and remaining members were selected in order to provide a range of expertise and perspectives. The task force included:
Ulric Neisser, Emory University (chair of the task force)
Gwyneth Boodoo, Educational Testing Service
Thomas J. Bouchard, Jr., University of Minnesota
A. Wade Boykin, Howard University
Nathan Brody, Wesleyan University
Stephen J. Ceci, Cornell University
Diane F. Halpern, California State University, San Bernadino
John C. Loehlin, University of Texas, Austin
Robert Perloff, University of Pittsburgh
Robert J. Sternberg, Yale University
Susana Urbina, University of North Florida
The 1995 report notes that all differences among members were resolved through extensive discussions, resulting in a report with the unanimous endorsement of task force members.
The report reviews research in five areas: Concepts of Intelligence, Intelligence Tests and Their Correlates, The Genes and Intelligence, Environmental Effects on Intelligence, and Group Differences.
In Concepts of Intelligence, the report reviews research and theory in five areas: psychometric approaches, multiple models, possible cultural variations, developmental conceptions, and biological perspectives.
Under the heading of Intelligence Tests and Their Correlates, the task force provides material that, in many ways, is a direct response to the analyses presented in The Bell Curve. This section provides an overview of test score characteristics and reviews research on the predictive validity of test scores in such areas as school performance, years of education, social status and income, job performance, and social outcomes. This section concludes with a discussion of research on test scores and their relationship with measures of cognitive processing speed.
The third section contains a review of research related to genetics and intelligence. This section is presented in two parts: First, sources of individual differences are discussed in concert with material on research methodology commonly applied to this topic (this is an excellent review). Second, research on the relationship between genetics and IQ scores is summarized.
The section on Environmental Effects consists of four parts: Social variables, biological variables, the Flynn Effect, and individual life experiences.
The final section of the report deals with group differences in intelligence, specifically in the areas of sex and ethnicity. This section concludes with a discussion about interpreting group differences.
The report concludes with a summary, which in turn concludes with a list of “unanswered questions” about intelligence (these questions are taken verbatim from a Web-based version of the report):
- Differences in genetic endowment contribute substantially to individual differences in (psychometric) intelligence, but the pathway by which genes produce their effects is still unknown. The impact of genetic differences appears to increase with age, but we do not know why.
- Environmental factors also contribute substantially to the development of intelligence, but we do not clearly understand what those factors are or how they work. Attendance at school is certainly important, for example, but we do not know what aspects of schooling are critical.
- The role of nutrition in intelligence remains obscure. Severe childhood malnutrition has clear negative effects, but the hypothesis that particular “micro-nutrients” may affect intelligence in otherwise adequately-fed populations has not yet been convincingly demonstrated.
- There are significant correlations between measures of information processing speed and psychometric intelligence, but the overall pattern of these findings yields no easy theoretical interpretation.
- Mean scores on intelligence tests are rising steadily. They have gone up a full standard deviation in the last fifty years or so, and the rate of gain may be increasing. No one is sure why these gains are happening or what they mean.
- The differential between the mean intelligence test scores of Blacks and Whites (about one standard deviation, although it may be diminishing) does not result from any obvious biases in test construction and administration, nor does it simply reflect differences in socio-economic status. Explanations based on factors of caste and culture may be appropriate, but so far have little direct empirical support. There is certainly no such support for a genetic interpretation. At present, no one knows what causes this differential.
- It is widely agreed that standardized tests do not sample all forms of intelligence. Obvious examples include creativity, wisdom, practical sense and social sensitivity; there are surely others. Despite the importance of these abilities we know very little about them: how they develop, what factors influence that development, how they are related to more traditional measures.
Press release from the American Psychological Association (http://www.apa.org/releases/intell.html)
Neisser, U., et al. (1995). Intelligence: Knowns and unknowns. Washington, DC: American Psychological Association. (Web version available at http://www.lrainc.com/swtaboo/taboos/apa_01.html)
Neisser, U., Boodoo, G., Bouchard, T. J., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51, 77-101.
Interested readers are encouraged to review the commentaries on the Neisser et al. article that appeared in the January 1997 issue of American Psychologist, Volume 52, Issue 1.
Written by Jonathan Plucker.
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