Aging isn’t always responsible for declines in mental function. In fact, some researchers believe simple genetics could play an even bigger role.

In a new study published in Nature, genetic material from about 2,000 people were gathered to find out how intelligence changes from childhood to adulthood. All of the participants took tests that measured their general intelligence at age 11 and then again when they were 65, 70, or 79.

After analyzing the results, researchers determined participants’ genes accounted for about 24 percent of mental changes across the life cycle. They also believe environment is an important role in shaping and maintaining intelligence and mental ability as we get older.

Ian J. Deary, PhD, a professor of psychology at the University of Edinburgh in the U.K., said, “The study will encourage those researchers looking for the genetic and environmental contributions to why some people’s cognitive functions age better than others.”

But while Clark McKown, PhD, director of the Rush NeuroBehavioral Center in Skokie, Ill., said the new study is “scientifically exciting and important,” he adds there are a lot of variables: “If we can figure out what the genetic [indicators] are of [mental] decline, and if we can develop a screening test, and if we can develop therapies, we may be able to screen people early in life and intervene to lower their risk.”

He also says eating a healthy diet, exercising regularly and maintaining an active social life can aid in mental acuity, regardless of our gene makeup.

And another Rush University neuropsychologist, S. Duke Han, PhD, agrees, adding, “It is not all in the genes. There is room for manipulation.”