We’re often told not to judge a book by its cover, but a new study published in the journal Psychological Science finds that some first impressions about honesty may be correct.
Researchers at the California Institute of Technology (Caltech) found that people are very good at detecting an unknown politician’s honesty just by looking at a photo of him. In the study, observers tended to perceive politicians with wider faces as more corruptible.
When the participants were shown photos of politicians they were not familiar with, they made better-than-chance judgments about whether those politicians had been convicted of corruption. Importantly, the participants made these judgments without knowing anything about the politicians or their careers.
“It might be difficult to understand why you can look at others’ faces and tell something about them,” says Chujun Lin, study co-author and Caltech graduate student. “But there is no doubt that people form first impressions from faces all the time. For example, on dating sites people often reject potential matches based on pictures without reading the profile.”
Facial width — technically, the facial width-to-height ratio — has been shown in previous research to be associated with aggressive behavior in men. In other words, men with wider faces have a greater tendency to be aggressive and threatening toward others than do men with thinner faces. Research has also shown that wide-faced men are perceived by others to be more threatening than those with thinner faces.
But while the research shows a connection between facial appearance and corruption, the researchers say it doesn’t necessarily mean that a corrupt-looking politician is more inherently corrupt. In fact, there could be many explanations.
One possibility is that if a face conveys a sense of dishonesty, the politician might be offered bribes more often. Another possibility is that corruptible-looking politicians are not any more corruptible than honest-looking politicians, but because of their looks they are more often suspected of, investigated for, and convicted of corruption.
“If a jury is deciding whether or not a politician is guilty, having a corruptible-looking face might create a negative impression, which might influence the jury’s decision,” says Lin, who adds that the “clean” politicians used in the study might not actually be clean. “Maybe they just haven’t been caught.”
In the first experiment, the researchers collected photos of 72 politicians who held office at the state or federal level. Half had been convicted of corruption and half had clean records. For consistency, all of the politicians included were male and Caucasian. All of the photos were black-and-white, cropped to the same size and featured a frontal, smiling portrait. The images were presented randomly to 100 participants, who were asked to rate each politician on how corruptible, dishonest, selfish, trustworthy, and generous they looked.
An analysis showed that the participants as a group were able to correctly detect the corrupt politicians from the clean politicians nearly 70 percent of the time based on their faces alone.
The second part of the study repeated the first experiment, but used photos of 80 politicians elected to state and local offices in California. Half had violated the California Political Reform Act — a law that regulates campaign finance, lobbying, and politicians’ conflicts of interest — and half had clean records. As before, the findings showed that the volunteers could correctly differentiate the corrupt politicians from the clean politicians nearly 70 percent of the time.
In a third experiment, the researchers used the photos from the first experiment but asked the participants to judge the politicians on a new set of criteria: corruptibility, aggressiveness, masculinity, competence, and ambitiousness.
The findings showed that only corruptibility-related trait inferences (inferences of corruptibility, dishonesty, selfishness, aggressiveness, generosity, and trustworthiness) differentiated corrupt politicians from the clean politicians. Inferences of competence, ambitiousness, or masculinity did not predict the politicians’ records.
In the fourth experiment, the researchers analyzed which of the politicians’ facial structures the volunteers associated with dishonesty and corruption. The faces were broken down into eight measures that described things like distance between the eyes, size of the cheekbones, nose length, and face width.
By comparing the data from those measures against the judgments made by the participants and the records of corruption convictions, the researchers made the discovery that politicians with greater facial-width ratios were more likely to be seen as corruptible.
To double check that face width was truly the characteristic driving these negative perceptions, the researchers gathered photos of 150 politicians and digitally manipulated each into a wide-faced version and a narrow-faced version.
The 450 resulting photos — including the 150 unaltered originals — were shown to 100 participants who were asked, as in the previous studies, to rate each image according to how corruptible the politician looked. And again, face width made the difference. The participants judged the wide-faced versions of the politicians to be more corruptible than their thin-faced counterparts.
“These findings raise many interesting questions for future research,” says Lin. “For example, what is the underlying causal mechanism of the correlation between perceived corruptibility and politicians’ records found in our study? Are politicians who look more corruptible more likely to be suspected, investigated, and even convicted?”
The findings might make a person wonder why corrupt politicians get elected in the first place if people can tell they’re corrupt just by looking at them. But the researchers say that a lot more than just a face goes into how you feel about a person.
“In the real world, you’re not just seeing a photo of a politician. You’re seeing them talk and move,” says co-author Ralph Adolphs, who is on the leadership team of the Tianqiao and Chrissy Chen Institute for Neuroscience. “Their face might make a first impression on you, but there are other factors that can come in and override that.”