The stress and mental challenge of complex jobs seem to pay off later in life. In their later years, people who spent their time in more demanding jobs had better memories and longer-lasting intellectual abilities, according to the results of a new study. People in menial jobs, which required little thought, tended to fall victim to age-related cognitive slippage.
As the Los Angeles Times writes, these findings lend support to the notion that—however much brain power people start with—they need to use it, in order not to lose it.
To arrive at these findings, researchers from Heriot-Watt University in Edinburgh turned to a large longitudinal study that began in Scotland in 1936, the LA Times describes. All of the children in the study had taken an IQ test when they were 11 years old, which gave the team a baseline measure of their intelligence, years before the kids began their professional careers.
Decades have since passed, and the team looked up around 1,000 of those original participants. All of them are now 70 years old, the LA Times continues. The group was evenly split between men and women. The researchers gave the now-retired participants another IQ test and several other standard intellect and memory tests. They also evaluated how cognitively challenging the participants' former jobs were, based on a preexisting scale.
Then, the team crunched the numbers to see what effect, if any, a person's job had on his or her intellect and memory later in life.
Those people who had jobs that required them to use their brains, the team found, fared significantly better in terms of their current memory and thinking skills, the LA Times reports. Because the team had the IQ data from early in life, they were able to control for differences in preexisting mental ability, as well as the tendency, for example, for smarter people to choose more challenging jobs.
While smarter people who went on the challenging jobs did reap the benefits, the team also found that those people with a lower IQ who went on to a challenging job had mental abilities that ranked above average, in the winter years of life. Those who started out with a higher score but went into a less challenging job, on the other hand, suffered for it in the long term.
This doesn't mean that everyone who has a complex job will be immune to the mentally degenerative effects of aging, however. The job factor, the team found, only accounted for about one to two percent of the variation the researchers found in their study subjects. But as the LA Times points out, that's about the same variation seen by those who do and don't smoke—a habit that's linked to lessened cognitive abilities later in life.