Conference examines mystery of rising intelligence scores

The news that intelligence test scores worldwide have risen steadily and significantly for nearly a century isn't quite as glorious as it may sound at first.

James Flynn of the University of Otago in New Zealand discussed the phenomenon of rising intelligence test scores as the opening speaker at a conference on "Intelligence on the Rise? Secular Changes in IQ and Related Measures" held on campus April 12-14 and organized by Woodruff Professor of Psychology Ulric Neisser.

In introducing Flynn, Neisser jokingly referred to the design of the conference as that of a "crazy quilt," because intelligence testing is no longer the exclusive domain of its creator, psychology, but of many disciplines including sociology, nutrition, genetics, philosophy and others.

Neisser also compared the current confusion over the meaning of rising intelligence test scores with the confusion the citizens of Pisa, Italy, felt centuries ago when their tower began to lean. "The first person to point out the fact that the tower was leaning was probably not welcomed by the tower building guild," he said. "But eventually no one could deny that it was leaning, even though no one knew why. We're in a similar position now when it comes to intelligence testing. Things are leaning in a way we don't entirely understand. We are used to thinking of intelligence as being fixed. But it turns out that things have shifted around a bit. I think that could probably be the motto for this conference."

The most visible manifestation of that shift, Flynn explained in his address, is a worldwide gain of about 18 IQ points between 1952 and 1982. What has the experts who study intelligence so baffled is that this increase in scores apparently has no corresponding increase in actual intelligence.

What is striking about these gains, Flynn said, is that they have been recorded in those who have taken tests that de-emphasize the role of culture and seek to measure fluid intelligence and problem-solving ability. "They don't measure crystallized intelligence," he said. While scores on tests that do measure school-taught, crystallized intelligence (such as the Wechsler and Stanford-Binet tests) have steadily risen over the same period, Flynn said, those increases on a worldwide basis are not nearly as dramatic as the "culture reduced," fluid measures of intelligence (such as Raven's Progressive Matrices).

The confounding mystery surrounding these gains in test scores, Flynn said, is that contemporary humans seem to be about as equally adept at functioning in their environments as humans from a century or two ago. So if the dramatic rises in intelligence test scores don't reflect any actual gains in the actual level of intelligence over the last 100 or 200 years, what do they indicate?

In proposing a theory to address the dilemma, Flynn used the example of juggling. He asked the audience to imagine a widespread, dramatic rise in juggling skills over a 30-year period in a culture that has taught absolutely nothing about the art of juggling. Although no "causal variable" would explain the existence of such a skill, Flynn said that a cultural emphasis on the sport of archery might explain the proficiency in juggling, because both activities require steady hands and nerves and the ability to focus intently.

"I feel certain that these gains in test scores don't have much to do with rising levels of intelligence," Flynn said. "But I know there must be something going on outside the test room."

Following Flynn's address, the remainder of the conference examined factors that may (or may not) be contributing to higher IQ scores, including nutrition, mother-child interaction and genetics.

--Dan Treadaway

Return to the April 22, 1996 contents page