In this New York Times article, Stephanie Coontz (Evergreen State College) says that knowing the average can be helpful – for example, one’s college paper is not as good as those written by most classmates, or most people my age don’t exercise as much as I do. “Averages are useful because many traits, behaviors, and outcomes are distributed in a bell-shaped curve,” says Coontz, “with most results clustered around the middle and a much smaller group of outliers at the high and low ends.”

            But averages can be misleading if a small number of disproportionately weighty outliers pull the average in one direction or the other. Some examples:

-   If Warren Buffett and Oprah Winfrey moved to a small Midwestern city, its average income would rise dramatically.

-   Most children of divorced parents turn out fine, but those who grow up to be very troubled (a small percent) exaggerate the impact of divorce in many people’s minds.

-   The most-common response to the death of a loved one is a sharp decline in personal well-being, followed by a slow, gradual recovery. But some people have a much more severe and long-lasting period of bereavement, others are ready to move on quite quickly, and a few actually experience an improvement in life satisfaction. Treating them all according to the “average” is a mistake.

-   On average, married people are happier than unmarried people, but is that a reason to promote marriage? It turns out that 80 percent of people who get married were happy in the first place. “More often, marriage seems to be a reward for having a high level of well-being than a route to attaining it,” says Coontz.

-   Single motherhood, on average, is stressful. But one study found that young, single, black and Hispanic mothers who married after the birth of a child were less healthy at the age of 40 than those who hadn’t married.

“I am not advocating that we give up on averages,” Coontz concludes. “Used cautiously, they help to analyze patterns and formulate policies. But given the variety of circumstances that exist in the messy real world, we ought to think twice before doling out one-size-fits-all advice to individuals on the basis of averages.”

“When Numbers Mislead” by Stephanie Coontz in The New York Times, May 26, 2013 (p. SR12), http://nyti.ms/17405bp

From the Marshall Memo #488