A new study suggests the explosive growth in knowledge experienced during adolescence results from brain development that allows inputs to be rapidly processed.
In short, just as computers work better with faster processors, adolescents become smarter because they become mentally quicker.
“Our findings make intuitive sense,” said lead author Thomas Coyle, who conducted the study with David Pillow, Anissa Snyder, and Peter Kochunov at University of Texas at San Antonio.
This is the first time psychologists have been able to confirm this important connection.
“Our research was based on two well-known findings,” Coyle said. “The first is that performance on intelligence tests increases during adolescence. The second is that processing speed”—the brain taking in and using new stimuli or information—”as measured by tests of mental speed also increases during adolescence.”
UTSA psychologists investigated the relationship between these findings by analyzing the results of 12 diverse intelligence and mental speed tests administered to 6,969 adolescents (ages 13 to 17).
Intelligence was measured by performance on cognitive tests of diverse abilities, such as vocabulary knowledge, math facts, and mechanical comprehension. Mental speed showed up in timed tests of computing and coding—matching digits and words and other arithmetic tasks.
In both of these categories, the researchers could see that the older teenagers did better and worked faster than the younger ones.
Additional analysis showed that the measured increase of intelligence could be accounted for almost entirely by the increase in mental speed.
The correlation or association is logical, says Coyle. After all, “performance on intelligence tests reflects, in part, the speed of acquiring knowledge, learning things, and solving problems.”
Those cognitive processes, he says, are related to how fast the brain is working—and all that improves during the teenage years.
The work reinforces earlier theories about the relationship between increasing processing speed in the maturing brain and the cognitive development of children.
The study appears in the forthcoming issue of Psychological Science, a journal published by the Association for Psychological Science.