MONDAY, Oct. 3 (HealthDay News) -- As teenagers mature, their mental speed improves, making them smarter, according to a new study.

Researchers at the University of Texas at San Antonio examined the performance of nearly 7,000 teenagers aged 13 to 17 on 12 different tests of intelligence and mental speed, including tasks involving math, vocabulary and problem-solving.

They found that older teenagers scored higher and worked faster than younger kids. After analyzing the tests, the older teens' increased intelligence could be almost entirely attributed to an increase in their mental speed, researchers said.

The study was published Sept. 19 in Psychological Science.

The study's authors concluded mental processes related to how fast the brain is working, such as the speed of acquiring knowledge, learning things, and solving problems, improve during the teenage years.

The findings make "intuitive sense," they added in a journal news release.

More information

The U.S. National Institute of Neurological Disorders and Stroke provides more information on the brain.