Everybody Lies

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Everybody Lies Page 16

by Seth Stephens-Davidowitz


  There is undoubtedly more to learn from zooming in on aspects of health and culture in different corners of the world. But my preliminary analysis suggests that Big Data will tell us that humans are even less powerful than we realized when it comes to transcending our biology. Yet we come up with remarkably different interpretations of what it all means.

  HOW WE FILL OUR MINUTES AND HOURS

  “The adventures of a young man whose principal interests are rape, ultra-violence, and Beethoven.”

  That was how Stanley Kubrick’s controversial A Clockwork Orange was advertised. In the movie, the fictional young protagonist, Alex DeLarge, committed shocking acts of violence with chilling detachment. In one of the film’s most notorious scenes, he raped a woman while belting out “Singin’ in the Rain.”

  Almost immediately, there were reports of copycat incidents. Indeed, a group of men raped a seventeen-year-old girl while singing the same song. The movie was shut down in many European countries, and some of the more shocking scenes were removed for a version shown in America.

  There are, in fact, many examples of real life imitating art, with men seemingly hypnotized by what they had just seen on-screen. A showing of the gang movie Colors was followed by a violent shooting. A showing of the gang movie New Jack City was followed by riots.

  Perhaps most disturbing, four days after the release of The Money Train, men used lighter fluid to ignite a subway toll booth, almost perfectly mimicking a scene in the film. The only difference between the fictional and real-world arson: In the movie, the operator escaped. In real life, he burned to death.

  There is also some evidence from psychological experiments that subjects exposed to a violent film will report more anger and hostility, even if they don’t precisely imitate one of the scenes.

  In other words, anecdotes and experiments suggest violent movies can incite violent behavior. But how big an effect do they really have? Are we talking about one or two murders every decade or hundreds of murders every year? Anecdotes and experiments can’t answer this.

  To see if Big Data could, two economists, Gordon Dahl and Stefano DellaVigna, merged together three Big Datasets for the years 1995 to 2004: FBI hourly crime data, box-office numbers, and a measure of the violence in every movie from kids-in-mind.com.

  The information they were using was complete—every movie and every crime committed in every hour in cities throughout the United States. This would prove important.

  Key to their study was the fact that on some weekends, the most popular movie was a violent one—Hannibal or Dawn of the Dead, for example—while on other weekends, the most popular movie was nonviolent, such as Runaway Bride or Toy Story.

  The economists could see exactly how many murders, rapes, and assaults were committed on weekends when a prominent violent movie was released and compare that to the number of murders, rapes, and assaults there were on weekends when a prominent peaceful movie was released.

  So what did they find? When a violent movie was shown, did crime rise, as some experiments suggest? Or did it stay the same?

  On weekends with a popular violent movie, the economists found, crime dropped.

  You read that right. On weekends with a popular violent movie, when millions of Americans were exposed to images of men killing other men, crime dropped—significantly.

  When you get a result this strange and unexpected, your first thought is that you’ve done something wrong. Each author carefully went over the coding. No mistakes. Your second thought is that there is some other variable that will explain these results. They checked if time of year affected the results. It didn’t. They collected data on weather, thinking perhaps somehow this was driving the relationship. It wasn’t.

  “We checked all our assumptions, everything we were doing,” Dahl told me. “We couldn’t find anything wrong.”

  Despite the anecdotes, despite the lab evidence, and as bizarre as it seemed, showing a violent movie somehow caused a big drop in crime. How could this possibly be?

  The key to figuring it out for Dahl and DellaVigna was utilizing their Big Data to zoom in closer. Survey data traditionally provided information that was annual or at best perhaps monthly. If we are really lucky, we might get data for a weekend. By comparison, as we’ve increasingly been using comprehensive datasets, rather than small-sample surveys, we have been able to home in by the hour and even the minute. This has allowed us to learn a lot more about human behavior.

  Sometimes fluctuations over time are amusing, if not earth-shattering. EPCOR, a utility company in Edmonton, Canada, reported minute-by-minute water consumption data during the 2010 Olympic gold medal hockey match between the United States and Canada, which an estimated 80 percent of Canadians watched. The data tells us that shortly after each period ended, water consumption shot up. Toilets across Edmonton were clearly flushing.

  Google searches can also be broken down by the minute, revealing some interesting patterns in the process. For example, searches for “unblocked games” soar at 8 A.M. on weekdays and stay high through 3 P.M., no doubt in response to schools’ attempts to block access to mobile games on school property without banning students’ cell phones.

  Search rates for “weather,” “prayer,” and “news” peak before 5:30 A.M., evidence that most people wake up far earlier than I do. Search rates for “suicide” peak at 12:36 A.M. and are at the lowest levels around 9 A.M., evidence that most people are far less miserable in the morning than I am.

  The data shows that the hours between 2 and 4 A.M. are prime time for big questions: What is the meaning of consciousness? Does free will exist? Is there life on other planets? The popularity of these questions late at night may be a result, in part, of cannabis use. Search rates for “how to roll a joint” peak between 1 and 2 A.M.

  And in their large dataset, Dahl and DellaVigna could look at how crime changed by the hour on those movies weekends. They found that the drop in crime when popular violent movies were shown—relative to other weekends—began in the early evening. Crime was lower, in other words, before the violent scenes even started, when theatergoers may have just been walking in.

  Can you guess why? Think, first, about who is likely to choose to attend a violent movie. It’s young men—particularly young, aggressive men.

  Think, next, about where crimes tend to be committed. Rarely in a movie theater. There have been exceptions, most notably a 2012 premeditated shooting in a Colorado theater. But, by and large, men go to theaters unarmed and sit, silently.

  Offer young, aggressive men the chance to see Hannibal, and they will go to the movies. Offer young, aggressive men Runaway Bride as their option, and they will take a pass and instead go out, perhaps to a bar, club, or a pool hall, where the incidence of violent crime is higher.

  Violent movies keep potentially violent people off the streets.

  Puzzle solved. Right? Not quite yet. There was one more strange thing in the data. The effects started right when the movies started showing; however, they did not stop after the movie ended and the theater closed. On evenings where violent movies were showing, crime was lower well into the night, from midnight to 6 A.M.

  Even if crime was lower while the young men were in the movie theater, shouldn’t it rise after they left and were no longer preoccupied? They had just watched a violent movie, which experiments say makes people more angry and aggressive.

  Can you think of any explanations for why crime still dropped after the movie ended? After much thought, the authors, who were crime experts, had another “Aha” moment. They knew that alcohol is a major contributor to crime. The authors had sat in enough movie theaters to know that virtually no theaters in the United States serve liquor. Indeed, the authors found that alcohol-related crimes plummeted in late-night hours after violent movies.

  Of course, Dahl and DellaVigna’s results were limited. They could not, for instance, test the months-out, lasting effects—to see how long the drop in crime might last. And it’s still possible that
consistent exposure to violent movies ultimately leads to more violence. However, their study does put the immediate impact of violent movies, which has been the main theme in these experiments, into perspective. Perhaps a violent movie does influence some people and make them unusually angry and aggressive. However, do you know what undeniably influences people in a violent direction? Hanging out with other potentially violent men and drinking.*

  This makes sense now. But it didn’t make sense before Dahl and DellaVigna began analyzing piles of data.

  One more important point that becomes clear when we zoom in: the world is complicated. Actions we take today can have distant effects, most of them unintended. Ideas spread—sometimes slowly; other times exponentially, like viruses. People respond in unpredictable ways to incentives.

  These connections and relationships, these surges and swells, cannot be traced with tiny surveys or traditional data methods. The world, quite simply, is too complex and too rich for little data.

  OUR DOPPELGANGERS

  In June 2009, David “Big Papi” Ortiz looked like he was done. During the previous half decade, Boston had fallen in love with their Dominican-born slugger with the friendly smile and gapped teeth.

  He had made five consecutive All-Star games, won an MVP Award, and helped end Boston’s eighty-six-year championship drought. But in the 2008 season, at the age of thirty-two, his numbers fell off. His batting average had dropped 68 points, his on-base percentage 76 points, his slugging percentage 114 points. And at the start of the 2009 season, Ortiz’s numbers were dropping further.

  Here’s how Bill Simmons, a sportswriter and passionate Boston Red Sox fan, described what was happening in the early months of the 2009 season: “It’s clear that David Ortiz no longer excels at baseball. . . . Beefy sluggers are like porn stars, wrestlers, NBA centers and trophy wives: When it goes, it goes.” Great sports fans trust their eyes, and Simmons’s eyes told him Ortiz was finished. In fact, Simmons predicted he would be benched or released shortly.

  Was Ortiz really finished? If you’re the Boston general manager, in 2009, do you cut him? More generally, how can we predict how a baseball player will perform in the future? Even more generally, how can we use Big Data to predict what people will do in the future?

  A theory that will get you far in data science is this: look at what sabermetricians (those who have used data to study baseball) have done and expect it to spread out to other areas of data science. Baseball was among the first fields with comprehensive datasets on just about everything, and an army of smart people willing to devote their lives to making sense of that data. Now, just about every field is there or getting there. Baseball comes first; every other field follows. Sabermetrics eats the world.

  The simplest way to predict a baseball player’s future is to assume he will continue performing as he currently is. If a player has struggled for the past 1.5 years, you might guess that he will struggle for the next 1.5 years.

  By this methodology, Boston should have cut David Ortiz.

  However, there might be more relevant information. In the 1980s, Bill James, who most consider the founder of sabermetrics, emphasized the importance of age. Baseball players, James found, peaked early—at around the age of twenty-seven. Teams tended to ignore just how much players decline as they age. They overpaid for aging players.

  By this more advanced methodology, Boston should definitely have cut David Ortiz.

  But this age adjustment might miss something. Not all players follow the same path through life. Some players might peak at twenty-three, others at thirty-two. Short players may age differently from tall players, fat players from skinny players. Baseball statisticians found that there were types of players, each following a different aging path. This story was even worse for Ortiz: “beefy sluggers” indeed do, on average, peak early and collapse shortly past thirty.

  If Boston considered his recent past, his age, and his size, they should, without a doubt, have cut David Ortiz.

  Then, in 2003, statistician Nate Silver introduced a new model, which he called PECOTA, to predict player performance. It proved to be the best—and, also, the coolest. Silver searched for players’ doppelgangers. Here’s how it works. Build a database of every Major League Baseball player ever, more than 18,000 men. And include everything you know about those players: their height, age, and position; their home runs, batting average, walks, and strikeouts for each year of their careers. Now, find the twenty ballplayers who look most similar to Ortiz right up until that point in his career—those who played like he did when he was 24, 25, 26, 27, 28, 29, 30, 31, 32, and 33. In other words, find his doppelgangers. Then see how Ortiz’s doppelgangers’ careers progressed.

  A doppelganger search is another example of zooming in. It zooms in on the small subset of people most similar to a given person. And, as with all zooming in, it gets better the more data you have. It turns out, Ortiz’s doppelgangers gave a very different prediction for Ortiz’s future. Ortiz’s doppelgangers included Jorge Posada and Jim Thome. These players started their careers a bit slow; had amazing bursts in their late twenties, with world-class power; and then struggled in their early thirties.

  Silver then predicted how Ortiz would do based on how these doppelgangers ended up doing. And here’s what he found: they regained their power. For trophy wives, Simmons may be right: when it goes, it goes. But for Ortiz’s doppelgangers, when it went, it came back.

  The doppelganger search, the best methodology ever used to predict baseball player performance, said Boston should be patient with Ortiz. And Boston indeed was patient with their aging slugger. In 2010, Ortiz’s average rose to .270. He hit 32 home runs and made the All-Star team. This began a string of four consecutive All-Star games for Ortiz. In 2013, batting in his traditional third spot in the lineup, at the age of thirty-seven, Ortiz batted .688 as Boston defeated St. Louis, 4 games to 2, in the World Series. Ortiz was voted World Series MVP.*

  As soon as I finished reading Nate Silver’s approach to predicting the trajectory of ballplayers, I immediately began thinking about whether I might have a doppelganger, too.

  Doppelganger searches are promising in many fields, not just athletics. Could I find the person who shares the most interests with me? Maybe if I found the person most similar to me, we could hang out. Maybe he would know some restaurants we would like. Maybe he could introduce me to things I had no idea I might have an affinity for.

  A doppelganger search zooms in on individuals and even on the traits of individuals. And, as with all zooming in, it gets sharper the more data you have. Suppose I searched for my doppelganger in a dataset of ten or so people. I might find someone who shared my interest in books. Suppose I searched for my doppelganger in a dataset of a thousand or so people. I might find someone who had a thing for popular physics books. But suppose I searched for my doppelganger in a dataset of hundreds of millions of people. Then I might be able to find someone who was really, truly similar to me.

  One day, I went doppelganger hunting on social media. Using the entire corpus of Twitter profiles, I looked for the people on the planet who have the most common interests with me.

  You can certainly tell a lot about my interests from whom I follow on my Twitter account. Overall, I follow some 250 people, showing my passions for sports, politics, comedy, science, and morose Jewish folksingers.

  So is there anybody out there in the universe who follows all 250 of these accounts, my Twitter twin? Of course not. Doppelgangers aren’t identical to us, only similar. Nor is there anybody who follows 200 of the accounts I follow. Or even 150.

  However, I did eventually find an account that followed an amazing 100 of the accounts I follow: Country Music Radio Today. Huh? It turns out, Country Music Radio Today was a bot (it no longer exists) that followed 750,000 Twitter profiles in the hope that they would follow back.

  I have an ex-girlfriend who I suspect would get a kick out of this result. She once told me I was more like a robot than a human being.


  All joking aside, my initial finding that my doppelganger was a bot that followed 750,000 random accounts does make an important point about doppelganger searches. For a doppelganger search to be truly accurate, you don’t want to find someone who merely likes the same things you like. You also want to find someone who dislikes the things you dislike.

  My interests are apparent not just from the accounts I follow but from those I choose not to follow. I am interested in sports, politics, comedy, and science but not food, fashion, or theater. My follows show that I like Bernie Sanders but not Elizabeth Warren, Sarah Silverman but not Amy Schumer, the New Yorker but not the Atlantic, my friends Noah Popp, Emily Sands, and Josh Gottlieb but not my friend Sam Asher. (Sorry, Sam. But your Twitter feed is a snooze.)

  Of all 200 million people on Twitter, who has the most similar profile to me? It turns out my doppelganger is Vox writer Dylan Matthews. This was kind of a letdown, for the purposes of improving my media consumption, as I already follow Matthews on Twitter and Facebook and compulsively read his Vox posts. So learning he was my doppelganger hasn’t really changed my life. But it’s still pretty cool to know the person most similar to you in the world, especially if it’s someone you admire. And when I finish this book and stop being a hermit, maybe Matthews and I can hang out and discuss the writings of James Surowiecki.

  The Ortiz doppelganger search was neat for baseball fans. And my doppelganger search was entertaining, at least to me. But what else can these searches reveal? For one thing, doppelganger searches have been used by many of the biggest internet companies to dramatically improve their offerings and user experience. Amazon uses something like a doppelganger search to suggest what books you might like. They see what people similar to you select and base their recommendations on that.

 

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