So, what makes you happy?

Research on the factors increasing or decreasing happiness has been of interest to psychologists and economists alike. Early research indicated that, contrary to our intuition, that major life events such as winning the lottery did not change our long-term ratings of our happiness. In other words, after a major life change, you will experience a temporary change in your happiness, but will return to being as happy as before the event. Such findings led to the set-point hypothesis that stated that each of us has an innate level of happiness, and that outside events, even large ones, don’t have a major influence on that set point.

Evidence for the set point hypothesis typically comes from longitudinal studies in which the same people rate their happiness each year, and report any major life events that occurred between surveys. From these data, you can correlate happiness as a function of the event by time-locking a sample population’s happiness the year an event occurs, and then seeing how it changes later. Let’s take marriage for example. Although each person in the sample gets married at a different time, the researcher can define year 0 to be the year of marriage for each person. Then, the researcher can look at this person’s happiness ratings both before and after marriage to determine the impact of marriage on happiness rankings. Below is the kind of graph that you get: planning and getting married makes people happy, and this happiness lasts for a couple of years, but after this, people go back to being however happy they were before.
Interestingly, although people hedonically adapt to marriage, they do not hedonically adapt to divorce. In other words, although marriage will not cause a permanent change in your happiness, getting a divorce will make you sadder in the long-term. Even more interesting is looking at the initial happiness ratings of people who marry and eventually divorce, and compare them to people who marry and stay married. It turns out that people who stay married were happier than their to-be-married-then-divorced friends even five years before marriage! This can be even before these people met their spouse.

Given that people do not strictly have one happiness set-point, what factors account for long-term changes in happiness? A new study in PNAS examines this question using 25 year longitudinal data from Germany. What I particularly enjoy about this study is that they focused on factors that people can control: although becoming disabled in an accident will likely lead to a long-term change in happiness, it is not something you can readily control. However, you do have control over things like your choice of romantic partner, your degree of religious involvement, your life priorities, whether you exercise, etc. Here is what they found:
-         Focusing on money can’t buy you happiness. People who rated the acquisition of material goods as very important were less happy than people focused on family or volunteerism. Women whose partners were materially focused were particularly sad.
-         You are less happy when you work more or (in particular) less than you would prefer to work.
-         Being with friends and exercising regularly can make you happy.
-         If you are a man, don’t be underweight. If you are a woman, don’t be obese.
-         Choose a partner who is not neurotic.
-         Although the study found a positive effect of religious participation, this is also correlated with altruism, family focus, and social participation, all of which independently increase happiness.

Although each of these factors had a small effect on happiness, all of them seem like good, common sense. I’ll go out for a run now.

Headey B, Muffels R, & Wagner GG (2010). Long-running German panel survey shows that personal and economic choices, not just genes, matter for happiness. Proceedings of the National Academy of Sciences of the United States of America, 107 (42), 17922-6 PMID: 20921399