Intelligence Tradeoff

We often think that adults are more intelligent than children, and in some ways, this is certainly true. But in the May 2005 issue of Child Development, Anna Fisher and Vladimir Sloutsky have shown one way in which adults are not smarter than kids.

Fisher and Sloutsky presented 30 pictures of various animals to 5, 7, and 11 year-olds as well as adults. Within each age, there were three groups: baseline, induction, and blocked categorization. The baseline group was asked simply to study the pictures for a subsequent memory test. The induction group was told that all cats have "beta cells" and were then shown the same group of pictures, but asked to specify whether each animal had beta cells or not. The categorization group was a control for the induction group, in which participants were shown a picture of a cat and told it was young; they were then asked to specify whether each of the other animals was young or not from the same group of pictures. Finally, all three groups went through a recognition phase in which they had to identify the pictures that were previously presented from those that had not been presented.

Interestingly, 5 and 7 year olds showed no decrease in recognition accuracy relative to baseline, and yet 11 year olds and adults showed a dramatic decrease. The authors take this as evidence that 11 year olds and adults spontaneously perform category based induction, while younger children perform similarity based induction. A second experiment in which the youngest children were taught to perform category based induction showed the same performance decrement as 11 year olds and adults. The authors also surmise that greater categorization ability may cause decreased recognition of individual items.

So it's possible that children have a better memory for individual items than adults, because they are still forming categorical boundaries between items on the basis of perceptual features.

In this and other studies, the relative "intelligence" of children and adults critically depends on the nature of the test; in fact, both children and adults may manifest different forms of intelligence, with different purposes, and any comparison between the two is one of apples and oranges.

In fact, the purpose of "child intelligence" is just to set the stage for the emergence of adult-like intelligence. If we want to enhance child development, we shouldn't be encouraging them to think like adults: we should be encouraging their child-like cognition, and allow those mechanisms to do what they've evolved to do. In other words, nurture nature.