Can we make ourselves smarter? In recent decades, scientists have accumulated increasing evidence that our intelligence, at least as measured by the IQ test, is sharply constrained by genetics. Although estimates vary, most studies place the heritability of intelligence at somewhere between 50% and 80%. It’s an uncomfortable fact, but not all brains are created equal.
Which is why there’s so much buzz about a forthcoming study that complicates this assumption. Researchers at the University of Michigan found that it’s possible to boost a core feature of human intelligence through a simple mental training exercise.
In fact, when several dozen elementary- and middle-school kids from the Detroit area used this exercise for 15 minutes a day, many showed significant gains on a widely used intelligence test.Most impressive, perhaps, is that these gains persisted for three months, even though the children had stopped training.
Scientists typically describe intelligence as consisting of two distinct components: fluid intelligence and crystallized intelligence. Fluid intelligence refers to the general ability to solve new problems and recognize unfamiliar patterns. Crystallized intelligence, by contrast, consists of particular kinds of knowledge. When children learn to count, for instance, they show gains on crystallized intelligence, even as their fluid intelligence remains constant. Scientists have typically regarded fluid intelligence as the aspect of our thinking that is most determined by genetics, since it can’t be easily taught.