Not, as it turns out, blacks. An analysis of more than 160 episodes reveals that black contestants, in both the early and late rounds of the game, are eliminated at a rate commensurate with their trivia-answering abilities. The same is true for female contestants. In a way, neither of these findings is so surprising. Two of the most potent social campaigns of the past half-century were the civil rights movement and the feminist movement, which demonized discrimination against blacks and women, respectively.

So perhaps, you say hopefully, discrimination was practically eradicated during the twentieth century, like polio.

Or more likely, it has become so unfashionable to discriminate against certain groups that all but the most insensitive people take pains to at least appear fair-minded, at least in public. This hardly means that discrimination itself has ended—only that people are embarrassed to show it. How might you determine whether the lack of discrimination against blacks and women represents a true absence or just a charade? The answer can be found by looking at other groups that society doesn’t protect as well. Indeed, the Weakest Link voting data do indicate two kinds of contestants who are consistently discriminated against: the elderly and Hispanics.

Among economists, there are two leading theories of discrimination. Interestingly, elderly Weakest Link contestants seem to suffer from one type, while Hispanics suffer the other. The first type is called taste-based discrimination, which means that one person discriminates simply because he prefers to not interact with a particular type of other person. In the second type, known as information-based discrimination, one person believes that another type of person has poor skills, and acts accordingly.

On The Weakest Link, Hispanics suffer information-based discrimination. Other contestants seem to view the Hispanics as poor players, even when they are not. This perception translates into Hispanics’ being eliminated in the early rounds even if they are doing well and not being eliminated in the later rounds, when other contestants want to keep the Hispanics around to weaken the field.

Elderly players, meanwhile, are victims of taste-based discrimination: in the early rounds and late rounds, they are eliminated far out of proportion to their skills. It seems as if the other contestants—this is a show on which the average age is thirty-four—simply don’t want the older players around.

It’s quite possible that a typical Weakest Link contestant isn’t even cognizant of his discrimination toward Hispanics and the elderly (or, in the case of blacks and women, his lack of discrimination). He is bound to be nervous, after all, and excited, playing a fast-moving game under the glare of television lights. Which naturally suggest another question: how might that same person express his preferences—and reveal information about himself—in the privacy of his home?

In a given year, some forty million Americans swap intimate truths about themselves with complete strangers. It all happens on Internet dating sites. Some of them, like Match.com, eHarmony.com, and Yahoo Singles, appeal to a broad audience. Others cater to more specific tastes: ChristianSingles.com, JDate.com, LatinMatcher.com, BlackSinglesConnection.com, CountryWesternSingles.com, USMilitarySingles.com, PlusSizeSingles.com, and Gay.com. Dating websites are the most successful subscription-based business on the Internet.

Each site operates a bit differently, but the gist is this: You compose a personal ad about yourself that typically includes a photo, vital statistics, your income range, level of education, likes and dislikes, and so on. If the ad catches someone’s fancy, that someone will e-mail you and perhaps arrange a date. On many sites, you also specify your dating aims: “long-term relationship,” “a casual lover,” or “just looking.”

So there are two massive layers of data to be mined here: the information that people include in their ads and the level of response gleaned by any particular ad. Each layer of the data can be asked its own question. In the case of the ads, how forthright (and honest) are people when it comes to sharing their personal information? And in the case of the responses, what kind of information in personal ads is considered the most (and least) desirable?

Two economists and a psychologist recently banded together to address these questions. Ali Hortaçsu, Günter J. Hitsch, and Dan Ariely analyzed the data from one of the mainstream dating sites, focusing on roughly 30,000 users, half in Boston and half in San Diego. Fifty-seven percent of the users were men, and the median age range for all users was twenty-six to thirty-five. Although they represented an adequate racial mix to reach some conclusions about race, they were predominantly white.

They were also a lot richer, taller, skinnier, and better-looking than average. That, at least, is what they wrote about themselves. More than 4 percent of the online daters claimed to earn more than $200,000 a year, whereas fewer than 1 percent of typical Internet users actually earn that much, suggesting that three of the four big earners were exaggerating. Male and female users typically reported that they are about an inch taller than the national average. As for weight, the men were in line with the national average, but the women typically said they weighed about twenty pounds less than the national average.

Most impressively, fully 70 percent of the women claimed “above average” looks, including 24 percent claiming “very good looks.” The online men too were gorgeous: 67 percent called themselves “above average,” including 21 percent with “very good looks.” This leaves only about 30 percent of the users with “average” looks, including a paltry 1 percent with “less than average” looks—which suggests that the typical online dater is either a fabulist, a narcissist, or simply resistant to the meaning of “average.” (Or perhaps they are all just realists: as any real-estate agent knows, the typical house isn’t “charming” or “fantastic,” but unless you say it is, no one will even bother to take a look.) Twenty-eight percent of the women on the site said they were blond, a number far beyond the national average, which indicates a lot of dyeing, or lying, or both.

Some users, meanwhile, were bracingly honest. Eight percent of the men—about 1 in every 12—conceded that they were married, with half of these 8 percent reporting that they were “happily married.” But the fact that they were honest doesn’t mean they were rash. Of the 258 “happily married” men in the sample, only 9 chose to post a picture of themselves. The reward of gaining a mistress was evidently outweighed by the risk of having your wife discover your personal ad. (“And what were you doing on that website?” the husband might bluster, undoubtedly to little avail.)

Of the many ways to fail on a dating website, not posting a photo of yourself is perhaps the most certain. (Not that the photo necessarily is a photo of yourself; it may well be some better-looking stranger, but such deception would obviously backfire in time.) A man who does not include his photo gets only one-fourth the volume of e-mail response of a man who does; a woman who doesn’t include her photo gets only one-sixth the response. A low-income, poorly educated, unhappily employed, not-very-attractive, slightly overweight, and balding man who posts his photo stands a better chance of gleaning some e-mails than a man who says he makes $200,000 and is deadly handsome but doesn’t post a photo. There are plenty of reasons someone might not post a photo—he’s technically challenged or is ashamed of being spotted by friends or is just plain unattractive—but as in the case of a brand-new car with a for-sale sign, prospective customers will assume he’s got something seriously wrong under the hood.