Everybody Lies: Big Data, New Data, and What the Internet Can Tell Us About Who We Really Are

Baseball-o- Phobe

How can two guys with such similar genes, raised by the same parents, in the same town, have such opposite feelings about baseball? What determines the adults we become? More fundamentally, what’s wrong with Noah? There’s a growing field within developmental psychology that mines massive adult databases and correlates them with key childhood events. It can help us tackle this and related questions. We might call this increasing use of Big Data to answer psychological questions Big Psych.

To see how this works, let’s consider a study I conducted on how childhood experiences influence which baseball team you support—or whether you support any team at all. For this study, I used Facebook data on “likes” of baseball teams. (In the previous chapter I noted that Facebook data can be deeply misleading on sensitive topics. With this study, I am assuming that nobody, not even a Phillies fan, is embarrassed to acknowledge a rooting interest in a particular team on Facebook.)

To begin with, I downloaded the number of males of every age who “like” each of New York’s two baseball teams. Here are the percent that are Mets fans, by year of birth.



The higher the point, the more Mets fans. The popularity of the team rises and falls then rises and falls again, with the Mets being very popular among those born in 1962 and 1978. I’m guessing baseball fans might have an idea as to what’s going on here. The Mets have won just two World Series: in 1969 and 1986. These men were roughly seven to eight years old when the Mets won. Thus a huge predictor of Mets fandom, for boys at least, is whether the Mets won a World Series when they were around the age seven or eight.

In fact, we can extend this analysis. I downloaded information on Facebook showing how many fans of every age “like” every one of a comprehensive selection of Major League Baseball teams.

I found that there are also an unusually high number of male Baltimore Orioles fans born in 1962 and male Pittsburgh Pirates fans born in 1963. Those men were eight-year-old boys when these teams were champions. Indeed, calculating the age of peak fandom for all the teams I studied, then figuring out how old these fans would have been, gave me this chart:



Once again we see that the most important year in a man’s life, for the purposes of cementing his favorite baseball team as an adult, is when he is more or less eight years old. Overall, five to fifteen is the key period to win over a boy. Winning when a man is nineteen or twenty is about one-eighth as important in determining who he will root for as winning when he is eight. By then, he will already either love a team for life or he won’t.

You might be asking, what about women baseball fans? The patterns are much less sharp, but the peak age appears to be twenty-two years old.

This is my favorite study. It relates to two of my most beloved topics: baseball and the sources of my adult discontent. I was firmly hooked in 1986 and have been suffering along—rooting for the Mets—ever since. Noah had the good sense to be born four years later and was spared this pain.

Now, baseball is not the most important topic in the world, or so my Ph.D. advisors repeatedly told me. But this methodology might help us tackle similar questions, including how people develop their political preferences, sexual proclivities, musical taste, and financial habits. (I would be particularly interested on the origins of my brother’s wacky ideas on the latter two subjects.) My prediction is that we will find that many of our adult behaviors and interests, even those that we consider fundamental to who we are, can be explained by the arbitrary facts of when we were born and what was going on in certain key years while we were young.

Indeed, some work has already been done on the origin of political preferences. Yair Ghitza, chief scientist at Catalist, a data analysis company, and Andrew Gelman, a political scientist and statistician at Columbia University, tried to test the conventional idea that most people start out liberal and become increasingly conservative as they age. This is the view expressed in a famous quote often attributed to Winston Churchill: “Any man who is under 30, and is not a liberal, has no heart; and any man who is over 30, and is not a conservative, has no brains.”

Ghitza and Gelman pored through sixty years of survey data, taking advantage of more than 300,000 observations on voting preferences. They found, contrary to Churchill’s claim, that teenagers sometimes tilt liberal and sometimes tilt conservative. As do the middle-aged and the elderly.

These researchers discovered that political views actually form in a way not dissimilar to the way our sports team preferences do. There is a crucial period that imprints on people for life. Between the key ages of fourteen and twenty-four, numerous Americans will form their views based on the popularity of the current president. A popular Republican or unpopular Democrat will influence many young adults to become Republicans. An unpopular Republican or popular Democrat puts this impressionable group in the Democratic column.

And these views, in these key years, will, on average, last a lifetime.

To see how this works, compare Americans born in 1941 and those born a decade later.

Those in the first group came of age during the presidency of Dwight D. Eisenhower, a popular Republican. In the early 1960s, despite being under thirty, this generation strongly tilted toward the Republican Party. And members of this generation have consistently tilted Republican as they have aged.

Americans born ten years later—baby boomers—came of age during the presidencies of John F. Kennedy, an extremely popular Democrat; Lyndon B. Johnson, an initially popular Democrat; and Richard M. Nixon, a Republican who eventually resigned in disgrace. Members of this generation have tilted liberal their entire lives.

With all this data, the researchers were able to determine the single most important year for developing political views: age eighteen.

And they found that these imprint effects are substantial. Their model estimates that the Eisenhower experience resulted in about a 10 percentage point lifetime boost for Republicans among Americans born in 1941. The Kennedy, Johnson, and Nixon experience gave Democrats a 7 percentage point advantage among Americans born in 1952.

I’ve made it clear that I am skeptical of survey data, but I am impressed with the large number of responses examined here. In fact, this study could not have been done with one small survey. The researchers needed the hundreds of thousands of observations, aggregated from many surveys, to see how preferences change as people age.

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