The first nineteen times that Henry Waxman, a California Democrat, ran for Congress, he won his seat with more than sixty per cent of the popular vote. That remarkable streak came to an end in 2012, the final election of his career, when he defeated his main rival, the independent Bill Bloomfield, by a comparatively small margin—fifty-four per cent to forty-six per cent. After serving nearly four decades in the House, during which he sponsored some six hundred pieces of legislation and chaired two powerful committees, Waxman came the closest he ever had to losing. But, according to a recent study in the journal Political Behavior, he was lucky in at least one respect. In the words of the study’s authors—Gabriel Lenz, a political scientist at the University of California, Berkeley, and his colleagues—Waxman “suffers from considerable appearance disadvantage.” If the 2012 ballot had shown a photograph of his face, their research showed, it would have cost him ten percentage points, enough to tip the race in Bloomfield’s favor.

Social scientists and natural philosophers have long recognized the existence of a so-called beauty premium (or, in some cases, an ugliness penalty). Attractive lawyers and M.B.A. grads earn more in their careers than their average-looking brethren, and when comely C.E.O.s appear on television, their companies often see a bump in stock price. The effect may be due in part to the human tendency to equate appearance with character. In the eighteenth century, for instance, a face was believed to reflect its owner’s moral standing. “Virtue beautifies, and vice renders a man ugly,” Johann Kaspar Lavater, a respected theologian and physiognomist, wrote. Charles Darwin, in his autobiography, confessed that he was nearly barred from travelling aboard H.M.S. Beagle, because its captain, “an ardent disciple of Lavater . . . doubted whether anyone with my nose could possess sufficient energy and determination for the voyage.” In “Ugliness: A Cultural History,” the historian Gretchen Henderson describes the rise around then of “ugly clubs,” where homely bachelors could share their sour grapes and poke fun at the hegemony of beauty. Members of the Ugly Face Clubb, which operated in Liverpool, England, were accepted by vote, the main requirement being “something odd, remarkable, droll, or out of the way in his phiz.” One member had a “Flook Mouth.” Another had a “Monstrous Long Nose resembling a Speaking Trumpet.”

Since those days, though, science’s understanding of beauty has grown more nuanced. Ugliness—or less-than-attractiveness, anyway—has made some important headway. In March, Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics, and Mary Still, an assistant professor of marketing and management at the University of Massachusetts Boston, analyzed earnings data from the National Longitudinal Survey of Adolescent Health, which took the measure of thousands of subjects at four intervals between the ages of seventeen and twenty-nine. Their analysis showed that more attractive individuals do earn more than less attractive people—but only if you don’t control for intelligence, health, and personality. Once you do, the seeming benefit of physical attractiveness disappears. The most surprising discovery, the researchers wrote, was “the unique nature of very unattractive individuals.” In most studies, unattractive and very unattractive people are lumped together; when Kanazawa and Still separated them into distinct categories, they found that, at every age, the ugliest three per cent of the population outearned the fifty per cent who were merely sort of ugly or just average-looking. They called this phenomenon the “ugliness premium.”

Last month, Ana Gheorghiu, a doctoral student at the University of Essex, and her colleagues published further evidence of the same effect. They randomly gathered some two hundred head shots of physicists and geneticists from university Web sites around the world, then had subjects rate the images based on perceived attractiveness and intelligence. Beauty, they found, did not confer credibility: the subjects showed more interest in the attractive scientists, but they deemed the uglier ones more likely to do good work. You might want Channing Tatum to give you a tour of the Large Hadron Collider, but you probably wouldn’t trust him to find the Higgs boson. The reason, it seems, is a variation on the nineteenth-century theme: we associate beauty with sociability. An attractive scientist is outgoing and engaging—which means he or she isn’t slaving over data in the lab, as a good empiricist should be. That conclusion, Gheorghiu and her co-authors point out, squares with evidence that attractive scholars receive higher marks as teachers but aren’t more successful in their research careers.

The ugliness premium does not, alas, seem to extend to politics, which many studies have shown to be a club for pretty faces. The typical experiment—including a classic paper from 2005 by Alexander Todorov, a Princeton psychologist and the author of a new book, “Face Value”—has subjects viewing head shots of unfamiliar politicians and rating them on their perceived competence. For the article in Political Behavior, Lenz and his colleagues tried a more direct strategy. As the day of the 2012 elections approached, they asked hundreds of prospective voters in both state and federal races to fill out mock ballots online. Half of them were given ballots identical to the ones they would receive in the voting booth; the others got ballots that included a black-and-white photo of each candidate’s face. Naturally, those whom the subjects deemed appealing received more mock votes.

The effect was sometimes stark. When I asked Lenz to elaborate on Waxman’s “appearance disadvantage,” he suggested that I Google “Waxman memes,” which turned up a series of photos of the congressman being compared unfavorably to horror-movie monsters, tardigrades, and naked mole rats. To be fair, a Google search for any politician, or pretty much anybody of note, will quickly serve up unflattering images, if not outright caricatures. And many of Waxman’s visual critics allude troublingly to the fact that he is Jewish. But the Waxman Effect isn’t limited to Waxman. Lenz and his co-authors note that, if the results from their mock elections were applied to the actual elections that year, twenty-nine per cent of primary races and fourteen per cent of races in the general election would have had a different outcome.

Curiously, the beauty premium seems to be of most benefit to politicians on the ideological right. Niclas Berggren, of the Research Institute of Industrial Economics, in Stockholm, and his colleagues recently performed the head-shot test on politicians from Finland, the European Parliament, and the United States. The more attractive candidates were not only likelier to have won their elections but also likelier to lean conservative. Why might this be true? Part of the answer may have to do with the effect that beauty has on the psyche. A pair of studies, one in 2011 and another in 2014, found that the more attractive people rated themselves as being, the less egalitarian they were in their outlook and the less they favored income redistribution. But it also appears that voters on the right tend to identify attractiveness with conservative views, and, when there’s little other information to go on, beauty plays a bigger role in their voting choices than it does for liberals.

Democrats might still find solace in the ugliness premium. Lenz summarized the situation in terms that Darwin might have appreciated. “There are such strong selection pressures for attractiveness,” he said. “My guess is that, in jobs where there’s a premium on looking good, if you see a funny-looking person there, they’ve got to be amazingly talented, because it’s the only way they could have gotten where they are. Henry Waxman”—who, he added, was highly regarded for his commitment and work ethic—“is a good example of that.”