New research finds Democrats aren't similarly swayed by facial stereotypes, which could give the party an advantage.

(Photo: Mandel Ngan/AFP/Getty Images)

As they choose candidates for the upcoming election, Democrats are looking for many qualities, including competence, character, and charisma. But new research suggests if they're looking for crossover votes, they might also want to consider another, less-obvious trait: whether the nominees look like Republicans.

"Having a deceptively Republican-looking face may help Democrats 'steal' Republican votes, without compromising their support among left-leaning voters," writes a research team led by Christopher Olivola of Carnegie Mellon University.

That's because Republicans—but not Democrats—are more likely to vote for a candidate who has the stereotypical facial figures of a member of their party. That conclusion, based on exit-poll data from 171 elections, emerges from a new study published in the journal Political Psychology.

It has been clear for nearly a decade that we make assumptions about the ideology of others based on their facial features. What's more, we're pretty good at it: A 2010 study found a student sample examining black-and-white photographs guessed right 60 percent of the time—considerably better than chance.

That, in turn, reflected our shorthand knowledge of what the two parties stand for. The researchers found people whose faces conveyed warmth were more likely to be pegged as Democrats, while those that projected power were more often seen as Republicans.

But does this really influence votes, given that voters can easily access information on the candidates' actual policy positions? Olivola found some evidence that it does in a 2012 study in which participants made hypothetical voting choices. This new research offers a real-world test.

He and his colleagues collected exit-poll data from 171 elections (in 2010 and 2016), noting the proportion of surveyed voters who selected the Democrat. How closely each candidate fit the stereotypical look of a party member was determined by a panel of 51 participants, who looked at photos of each pair of opposing candidates, and guessed which was the Democrat and which the Republican.

"For each election," they write, "the proportion of participants who incorrectly labeled the Democrat a Republican (was used as a marker for) how deceptively Republican-looking the Democratic candidate's face was."

The key result: "Republicans were more likely to vote for a Democrat, the more that person had a (relatively) Republican-looking face." In contrast, "Democratic voters' choices were unrelated to these political facial stereotypes."

This was true in red, blue, and purple states, and remained valid even after taking into account the candidates' age, gender, and ethnicity. The effect was also "unrelated to how attractive, honest, and dependable their faces looked."

It's not at all clear why Republicans and Democrats respond differently to these visual signals.

"Our results should not be interpreted to imply that Republican voters are generally more superficial (and thus) more likely to vote based on appearances," Olivola and his colleagues warn.

They note previous research has found members of both parties "are more likely to vote for candidates who have more competent-looking faces." On that metric, both are equally susceptible to being swayed by looks.

It will take time, and more research, to tease out why this particular cue only effects Republicans. But Democratic strategists can utilize this insight right now, as they search for the most electable candidate in each competitive Congressional district.

One who looks like a Republican, but votes like a Democrat, might be just the ticket.