PsychNotes Index

More PsychNotes: Policies and Issues in Mental Health

What Causes People to Live Longer When They Retire Later? Limitations of Research
by Monica A. Frank, PhD

I don't know about you but when I see a Wall Street Journal headline “Retiring After 65 May Extend Life” I take it to mean that waiting to retire will make me live longer. However, that is not what this research actually indicated. This is a good example of how media inaccurately interprets research and why I get frustrated with the information being provided to the public.

Research studies can examine whether something causes something else or whether it is related to something else. These are very important differences that even major news outlets can get wrong. Most studies are what is called “correlational” because those studies are easier to do. Such studies look at whether one thing is related to another. But not whether it causes another.

A common example used is that gun violence increases in the inner cities during the summer time. Many people have taken this correlation to mean that high temperatures cause increased aggression. However, when examined further, the reason gun violence increases in the summer could be due to schools are closed and more people are out on the streets with more opportunity for altercations.

You might ask why correlational research is relied upon so much. The answer has to do with time, funding, and difficulty of conducting more rigorous research. For instance, a questionnaire which can be cheap and easy can provide correlational information. Whereas research that determines causality needs to use random group assignment.

In this research, to determine whether retiring later causes a person to live longer it would be necessary to have a group of equally healthy people and divide them into two groups with a flip of a coin: one group retires at 65 and one group retires later. You can see how it would be difficult to get people to agree to participate in such research.

That's not to say correlational research isn't valuable but we need to keep in mind the limitations of such studies. For instance, what we might be able to infer from this correlational research is that people who retire after 65 live longer but not that retiring after 65 causes people to live longer. In fact, it may be some other quality that causes people to decide to retire after 65 such as personality, attitude, engagement with life or desire to contribute meaningfully. Even though correlational research can examine whether there were differences between the groups, it still cannot tell us that later retirement causes a longer life.

Of course, maybe I'm just a stickler. I know some people will say, “What does it matter? So what if I believe that retiring after 65 will cause me to live longer—that might be a good thing to believe.” But this might matter when it comes to other types of information such as health or public policy.

When you believe whatever you are told without question, then you are subject to manipulation by other people's agendas. Understanding how the information is obtained can help you make decisions for yourself about what is best for you.