Intelligence: Knowns and Unknowns
After the publication of The Bell Curve (1994) and the following public debate, the Board of Scientific Affairs (BSA) of the American Psychological Association concluded that there were "serious misunderstandings" and "that there was urgent need for an authoritative report on these issues—one that all sides could use as a basis for discussion". Furthermore, "Another unfortunate aspect of the debate was that many participants made little effort to distinguish scientific issues from political ones, Research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications." The report stated that "The charge to our Task Force was to prepare a dispassionate survey of the state of the art: to make clear what has been scientifically established, what is presently in dispute, and what is still unknown. In fulfilling that charge, the only recommendations we shall make are for further research and calmer debate."
The report was originally published on 7 August 1995. It was authored by a task force of 11 experts. Three of the experts were also among the 52 signatories to "Mainstream Science on Intelligence", a similar, although much shorter statement by 52 professors who were all experts in intelligence and allied fields. The entire Task Force gave unanimous support to the final report. An edited version of the report was published in the journal American Psychologist in February 1996.
The 24 pages long report, linked to in the external links section below, discussed both intelligence and IQ research in general as well as group differences. The report cited many sources from the scientific literature on these topics.
Regarding the politically most sensitive issue, race and intelligence research, or more specifically the US Black-White IQ gap, the APA report stated that there was a long-standing 15 IQ points or 1 standard deviation gap, although it might have narrowed slightly in the then recent years. The difference was largest on those tests, verbal or non-verbal, that best represented the general intelligence factor (g). Controlled studies of the way the tests were formulated and administered had shown that this did not contribute substantially to the difference. Attempts to devise tests that would minimize disadvantages of this kind had been unsuccessful. The scores predicted future achievement equally well for Blacks and Whites. "The cause of that differential is not known; it is apparently not due to any simple form of bias in the content or administration of the tests themselves. The Flynn effect shows that environmental factors can produce differences of at least this magnitude, but that effect is mysterious in its own right. Several culturally based explanations of the Black/ White IQ differential have been proposed; some are plausible, but so far none has been conclusively supported. There is even less empirical support for a genetic interpretation. In short, no adequate explanation of the differential between the IQ means of Blacks and Whites is presently available."
The report cited Eyfrath's 1959 study on the children of German White mother and "Black" fathers as well as two studies from 1970s on blood groups and racial admixture as evidence against the partially-genetic explanation. These studies are discussed in the "Racial admixture" section in the Race and intelligence: The genetics or not debate article.
In 2002, in an interview, the psychologist and supporter of a partially-genetic explanation for the racial IQ gaps, Arthur Jensen, was asked about how he interpreted the APA task force's statements. Jensen responded:
- "As I read the APA statement, [...] I didn't feel it was contradicting my position, but rather merely sidestepping it. It seems more evasive of my position than contradictory. The committee did acknowledge the factual status of what I have termed the [Spearman Effect, the reality of g, the inadequacy of test bias and socioeconomic status as causal explanations, and many other conclusions that don't differ at all from my own position. [...] Considering that the report was commissioned by the APA, I was surprised it went as far as it did. Viewed in that light, I am not especially displeased by it."
- Race and intelligence
- "Mainstream Science on Intelligence"
- Statement on "Race" - A brief, politically correct statement, lacking any source, proclaimed in 1998 by the leftist and highly political American Anthropological Association.
- Neisser, Ulrich; Boodoo, Gwyneth; Bouchard, Thomas J.; Boykin, A. Wade; Brody, Nathan; Ceci, Stephen J.; Halpern, Diane F.; Loehlin, John C.; Perloff, Robert; Sternberg, Robert J.; Urbina, Susana (1996). "Intelligence: Knowns and Unknowns". American Psychologist. 51:77–101.
- Miele, Frank (2002). Intelligence, Race, and Genetics: Conversations with Arthur R. Jensen. Oxford: Westview Press. ISBN 0-8133-4274-0.