SAN ANTONIO, Sept. 29 (UPI) -- U.S. researchers say they have demonstrated for the first time that adolescents become smarter because their brains process information faster.
Researchers David Pillow, Anissa Snyder and Peter Kochunov -- psychologists at University of Texas at San Antonio -- said their findings make intuitive sense.
"Our research was based on two well-known findings," Coyle said in a statement. "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."
To find the relationship between these two phenomena, the psychologists analyzed the results of 12 diverse intelligence and mental speed tests administered to 6,969 adolescents ages 13-17 in the 1997 National Longitudinal Survey of Youth.
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.
The study, published in the journal Psychological Science, found in both of these categories, the researchers could see the older teenagers did better and worked faster than the younger ones. Running the data in numerous ways, the study discovered the measured increase of intelligence could be accounted for almost entirely by the increase in mental speed.