Does Early Retirement Lead to Brain Fade?

Retiring early may ease your stress and give you freedom, but it probably isn't the smartest move if you hope to keep your mental edge.

In fact, quitting the workplace is likely to cost you IQ points, according to a nation-by-nation comparison of how cognitive abilities decline with age. The federally funded research, touted as the first of its kind, examined people between the ages of 60 and 64 -- a point in life when many Americans are still on the job, while individuals in countries such as Austria and France are often tending their gardens.

The result: Americans and other later-working people, including Greeks and Danes, scored substantially better on tests of short-term memory, abstract reasoning and mental quickness -- the sort of think-on-your-feet skills that help you cope with a fast-moving world.

"It's a very large effect -- it's very significant and very big," says Susann Rohwedder, co-author of the findings, published in the winter edition of the Journal of Economic Perspectives.

Rohwedder, an associate director of the RAND Center for the Study of Aging in Santa Monica, wrote the report along with Robert J. Willis, an economics professor at the University of Michigan, based on data pooled from several longitudinal studies of aging and health in the United States and Europe. More than 50,000 people were surveyed in 13 nations, from which Rohwedder and Willis focused on 8,800 people who met their age criteria.

Although the results might seem to be bad news for those out of the work force, Rohwedder sees hope for everyone in these new insights into the brain. "The basic question is, 'Is cognitive decline with age something we cannot influence -- or is there something we can do about it?'" she says. "This shows that cognitive decline can be influenced. To some extent it's in our hands, and I think that's actually great news."

Is the Brain Like a Bicep?

Studying how the brain ages has been notoriously difficult because so many factors are suspected of influencing mental performance -- genetics, diet, overall health and the myriad different challenges any given brain must face, which cannot be compared equally. While it is known that cognitive abilities dim over time, it is nearly impossible to see why they dim and what, if anything, might slow the process.

Some scholars liken the brain to a bicep that can be strengthened with regular use. Others suggest that intellectual capacity may remain unaffected by whether we choose to toil over algebraic problems or watch sailboats go by.

As part of their research, Rohwedder and Willis attempted to eliminate as many confusing variables as possible by examining data from large, random groups where most individual differences would cancel out. Subjects fell into one of two categories -- those who had retired and those who had not. When given 20-point memorization tests, active workers averaged about 12 correct answers, while retirees got only eight right.

The relatively large gap between the two groups -- 4½ points -- indicates that retirees lose some of their mental keenness fairly quickly, Rohwedder says. She declined to say how such a drop would translate into IQ scores, but her article, titled "Mental Retirement," concludes by noting, "The estimated effect of retirement on cognition . . . is very large indeed."

"I was surprised, to be honest, at the findings and the magnitude of the findings," says Richard Suzman, director of behavioral and social research at the National Institute on Aging, which funded much of the work. Further research is needed, he says, to understand why active employees scored so much better. "It's unclear, for example, whether it's the cognitive challenge of work, whether it's the social engagement, or whether it's aerobic exercise people get on the job," Suzman says. "Is it the sense of purpose?"

Earlier studies have linked retirement with depression in some people, which might affect intellectual performance. "What happens if people retire from a rather dull, mind-numbing job, and start a hobby or volunteer activity in which they are more intellectually challenged?" Suzman says. "Would they do better?"

More Research To Be Done

Because so much remains unknown, some experts view the study's conclusions with skepticism. Dr. Richard W. Besdine, medical director of the American Federation for Aging Research in New York, points out that the reasons for retirement vary widely. In many cases, the loss of cognitive ability may cause someone to stop working, rather than retirement triggering the mental decline.

"We don't know a lot about this, and it's a tough area to do work in," Besdine says. The study also fails to measure every type of intelligence. As the authors point out, psychologists identify two major categories: "fluid intelligence," which refers to abstract-reasoning powers and the ability to recall and process information in real time, and "crystalized intelligence," which consists of learned skills and vocabulary, for example. The memory tests used in the research measure only fluid intelligence. Crystalized intelligence, which was not studied, peaks later in life and is often slower to decline. Rohwedder acknowledges that someone who retires and spends a great deal of time reading, for example, may find it possible to improve their learned skills despite losing some processing speed.

Whether adults also can amp up their fluid intelligence -- or at least slow its decline -- by doing crossword puzzles and other mental gymnastics is still to be learned, experts say.

"We do know that doing crossword puzzles, Sudoku and memory exercises helps you do crossword puzzles, Sudoku and memory exercises," says Suzman of the National Institute on Aging. "But there's no convincing evidence that it prevents or slows cognitive decline generally."

Nor is there strong reason to believe that staying mentally active will prevent or delay Alzheimer's Disease or other forms of dementia.

"There's some evidence, but it's weak," says Besdine, who, despite his doubts, thinks there is a decent chance the brain may turn out to be like a bicep. If so, people might benefit by filling their retirement with the sorts of stimulation they found at work -- challenging tasks, social interaction, exercise and whatever else keeps them engaged with life.

"Use your brain -- it's probably good for you," Besdine says. "And it's fun."

SecondAct contributor David Ferrell is a former Los Angeles Times staff writer and the author of Screwball, a comic baseball novel.