A new study suggests that people with complex jobs have better cognitive abilities later in life.

Researchers at the School of Life Sciences at Heriot-Watt University in Edinburgh, Scotland, involved 1,066 people in the study and were grouped depending on job complexity: complex jobs versus less complex jobs.

Complex jobs included lawyers, architects, graphic designers and engineers, which require organizing data, while the less complex jobs included typists, factory workers, food servers and telephone operators, who do more copying and comparing of data.

The average age of the participants was 70 and all of them took cognitive assessments to measure their general knowledge, speed and memory. The researchers also considered education, criminal records, access to services and IQ when they were 11 years old.

"The association between more complex jobs and better cognitive outcomes is reduced, but there remains a small additional benefit for our cognitive abilities from being in more complex jobs," said study author Alan Gow, Gow, an assistant professor of psychology at the School of Life Sciences at Heriot-Watt University in Edinburgh, Scotland, to Reuters Health in an email.

The analysis showed that regardless of child IQ and other factors, those with complex jobs performed better in memory and thinking assessments compared to those with less complex jobs. But overall, the difference wasn't that staggering as it was only about 1 or 2 percent.

"These results actually provide evidence for both theories," Gow said in a news release. "Factoring in people's IQ at age 11 explained about 50 percent of the variance in thinking abilities in later life, but it did not account for all of the difference. That is, while it is true that people who have higher cognitive abilities are more likely to get more complex jobs, there still seems to be a small advantage gained from these complex jobs for later thinking skills."

This study was published in the December issue of Neurology.