When a scientist says one thing causes another, it is time to sit up and take notice. To scientists, saying something causes something is much stronger and definitive than saying it is merely correlated. Scientific researchers are very cautious, and they require strong evidence before they can say one thing causes another. Most of the time researchers play it safe and say that two events or factors are correlated.
Correlation certainly implies a relationship between two factors and means they are linked. When you see one factor, you most likely will see the other. The frequency with which the two factors are linked determines the strength of the correlation. There's a mathematical formula for that.
Causality is a totally different situation. Causality means that one factor brings about the other factor.
When a scientist says one thing causes another, take notice.
Now, researchers Susann Rohwedder and Robert J. Willis are saying that retiring early, such as in a person's early 60s, causes cognitive decline. There is major significance in this finding. It has large implications for the quality of life of the aged population.
After all, retirement is usually associated with "the good life." What if retired life isn't so good, after all, because of accelerated mental decline? Isn't it better to wait?
Let's look at what the researchers found, what they are saying, and how it may affect a person who is considering early retirement or who has already taken early retirement and stopped working for pay.
Researchers Rohwedder and Willis say retiring in a person's early 60s causes cognitive decline.
As scientists, the researchers considered other possibilities. They thought there might be a chance that large numbers of early retirees retire early because they are already in mental decline, and they know it. They find themselves making mistakes on the job, or find the work too frustrating to keep up; they are resistant to learning new technologies, etc. This would mean that mental decline causes early retirement-not the other way around.
The researchers made sure that none of those factors came into the equation. They worked their data so as to account for that possibility as well as others. What they found was that "on average, retirement causes a decrease in a person's cognitive ability relative to staying in the labor force." In fact, the researchers say retirement is associated with a reduction in memory of almost 5 points on a scale of 20 when compared to those who are still working for pay. When it comes to the ability to recall words, there is also a large decline among those who retire in their early sixties.
Forget all the advice about doing crossword puzzles or playing complex card games, the researchers say. That hasn't been proven to work. Once someone is in an "unengaged lifestyle," as the scientists call it, the change is so huge that such activities won't stave off the decline.
What if retired life isn't so good because of accelerated mental decline? Isn't it better to wait?
The scientists note that the United States is currently undergoing a sea change when it comes to retirement. For the past century, Americans have retired as early as possible. Now they are trending toward retiring quite a bit later. The scientists note that this is a wonderful development for seniors' standards of living. It also helps society by lifting some of the financial burden off Social Security and Medicare. Equally important is the fact that older people themselves benefit from working longer because their minds stay sharp.
When most of us picture retirement, we do not think of forgetfulness, being unable to remember what we wanted to say because our word recall is stalled, or being unable to think our way through the problems that life presents us. We imagine ourselves free to pursue our own hopes and dreams. That happy portrait of retirement seems more possible and achievable when retirement is delayed.
Rohwedder, Susann., Willis, Robert J. Mental Retirement. Journal of Economic Perspectives. 2010: 24(1): pp. 119-138. Available online through the U.S. National Library of Medicine, National Institutes of Health, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958696/.