There are countless ways to make yourself feel lousy. Here's one more, according to research out of Stanford: Assume you're alone in your unhappiness.

"Misery Has More Company Than People Think," a paper in the January issue of Personality and Social Psychology Bulletin, draws on a series of studies examining how college students evaluate moods, both their own and those of their peers. Led by Alex Jordan, who at the time was a Ph.D. student in Stanford's psychology department, the researchers found that their subjects consistently underestimated how dejected others were–and likely wound up feeling more dejected as a result. Jordan got the idea for the inquiry after observing his friends' reactions to Facebook: He noticed that they seemed to feel particularly crummy about themselves after logging onto the site and scrolling through others' attractive photos, accomplished bios, and chipper status updates. "They were convinced that everyone else was leading a perfect life," he told me.

The human habit of overestimating other people's happiness is nothing new, of course. Jordan points to a quote by Montesquieu: "If we only wanted to be happy it would be easy; but we want to be happier than other people, which is almost always difficult, since we think them happier than they are." But social networking may be making this tendency worse. Jordan's research doesn't look at Facebook explicitly, but if his conclusions are correct, it follows that the site would have a special power to make us sadder and lonelier. By showcasing the most witty, joyful, bullet-pointed versions of people's lives, and inviting constant comparisons in which we tend to see ourselves as the losers, Facebook appears to exploit an Achilles' heel of human nature. And women—an especially unhappy bunch of late—may be especially vulnerable to keeping up with what they imagine is the happiness of the Joneses.

In one of the Stanford studies, Jordan and his fellow researchers asked 80 freshmen to report whether they or their peers had recently experienced various negative and positive emotional events. Time and again, the subjects underestimated how many negative experiences ("had a distressing fight," "felt sad because they missed people") their peers were having. They also overestimated how much fun ("going out with friends," "attending parties") these same peers were having. In another study, the researchers found a sample of 140 Stanford students unable to accurately gauge others' happiness even when they were evaluating the moods of people they were close to—friends, roommates and people they were dating. And in a third  study, the researchers found that the more students underestimated others' negative emotions, the more they tended to report feeling lonely and brooding over their own miseries. This is correlation, not causation, mind you; it could be that those subjects who started out feeling worse imagined that everyone else was getting along just fine, not the other way around. But the notion that feeling alone in your day-to-day suffering might increase that suffering certainly makes intuitive sense.

As does the idea that Facebook might aggravate this tendency. Facebook is, after all, characterized by the very public curation of one's assets in the form of friends, photos, biographical data, accomplishments, pithy observations, even the books we say we like. Look, we have baked beautiful cookies. We are playing with a new puppy. We are smiling in pictures (or, if we are moody, we are artfully moody.) Blandness will not do, and with some exceptions, sad stuff doesn't make the cut, either. The site's very design—the  presence of a "Like" button, without a corresponding "Hate" button—reinforces a kind of upbeat spin doctoring. (No one will "Like" your update that the new puppy died, but they may "Like" your report that the little guy was brave up until the end.)

Any parent who has posted photos and videos of her child on Facebook is keenly aware of the resulting disconnect from reality, the way chronicling parenthood this way creates a story line of delightfully misspoken words, adorably worn hats, dancing, blown kisses. Tearful falls and tantrums are rarely recorded, nor are the stretches of pure, mind-blowing tedium. We protect ourselves, and our kids, this way; happiness is impersonal in a way that pain is not. But in the process, we wind up contributing to the illusion that kids are all joy, no effort. 

Facebook is "like being in a play. You make a character," one teenager tells MIT professor Sherry Turkle in her new book on technology, Alone Together. Turkle writes about the exhaustion felt by teenagers as they constantly tweak their Facebook profiles for maximum cool. She calls this "presentation anxiety," and suggests that the site's element of constant performance makes people feel alienated from themselves. (The book's broader theory is that technology, despite its promises of social connectivity, actually makes us lonelier by preventing true intimacy.)

Facebook oneupsmanship may have particular implications for women. As Meghan O'Rourke has noted here in Slate, women's happiness has been at an all-time low in recent years. O'Rourke and two University of Pennsylvania economists who have studied the male-female happiness gap argue that women's collective discontent may be due to too much choice and second-guessing–unforeseen fallout, they speculate, of the way our roles have evolved over the last half-century. As the economists put it, "The increased opportunity to succeed in many dimensions may have led to an increased likelihood in believing that one's life is not measuring up."

If you're already inclined to compare your own decisions to those of other women and to find yours wanting, believing that others are happier with their choices than they actually are is likely to increase your own sense of inadequacy. And women may be particularly susceptible to the Facebook illusion. For one thing, the site is inhabited by more women than men, and women users tend to be more active on the site, as Forbes has reported. According to a recent study out of the University of Texas at Austin, while men are more likely to use the site to share items related to the news or current events, women tend to use it to engage in personal communication (posting photos, sharing content "related to friends and family"). This may make it especially hard for women to avoid comparisons that make them miserable. (Last fall, for example, the Washington Post ran a piece about the difficulties of infertile women in shielding themselves from the Facebook crowings of pregnant friends.)

Jordan, who is now a postdoctoral fellow studying social psychology at Dartmouth's Tuck School of Business, suggests we might do well to consider Facebook profiles as something akin to the airbrushed photos on the covers of women's magazine. No, you will never have those thighs, because nobody has those thighs. You will never be as consistently happy as your Facebook friends, because nobody is that happy. So remember Montesquieu, and, if you're feeling particularly down, use Facebook for its most exalted purpose: finding fat exes.

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