Defining “Intelligence” – a controversial saga (part 1)

Defining “Intelligence” is a controversial saga that is more entertaining than day-time soap.  In 1994, a group of academic researchers in fields allied to intelligence testing issued a public statement “Mainstream Science on Intelligence.”  This documents, originally published in Wall Street Journal,  documented key conclusions widely accepted in the expert community. (It was a response to what the authors viewed as the inaccurate and misleading reports made by the media.)  52 university professors specializing in intelligence and related fields, including one-third of the editorial board of the journal Intelligence, signed the open letter.

But the public drama of scientists vs. media didn’t stop there. The letter to the Wall Street Journal also set out 25 conclusions.  There is a short summary of several that most people would consider controversial statements about race, genetics and intelligence.  Mis-quoted or worse, purposefully mis-communicated with malicious intent, these could be really damaging statements.

  1. “The bell curve for whites is centered roughly around IQ 100; the bell curve for American blacks roughly around 85; and those for different subgroups of Hispanics roughly midway between those for whites and blacks. The evidence is less definitive for exactly where above IQ 100 the bell curves for Jews and Asians are centered”
  2. “… genetics plays a bigger role than environment in creating IQ differences”
  3. “Racial-ethnic differences in IQ bell curves are essentially the same when youngsters leave high school as when they enter first grade … black 17-year-olds perform, on the average, more like white 13-year-olds”
  4. “Almost all Americans who identify themselves as black have white ancestors – the white admixture is about 20% … research on intelligence relies on self-classification into distinct racial categories”

Not to be outdone, American Psychological Association rushed unto the stage. Intelligence: Knowns and Unknowns was a 1995 report issued by an 11-expert task force created by the APA. (3 were signatories on Mainstream Science on Intelligence.)  Concerned about “…research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications,” the task force decided on the following definition:

Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person’s intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of “intelligence” are attempts to clarify and organize this complex set of phenomena. Although considerable clarity has been achieved in some areas, no such conceptualization has yet answered all the important questions, and none commands universal assent.

One thing worthy to note in the length APA paper, task force did not include the idea that genetics play a significant role in the appearance of between-group differences in IQ.  Some people feels APA merely side-stepped the issue by passively omitting the wording of the statement. This group would love to see APA declare strongly that race/genetic/heredity is NOT a factor so no one can read in between the lines.

Who knows science can be this much fun?  Next up, we will tackle the 5 or 6 or 7 major intelligence theories. (Hint, no body can seemed to agree on the number.)