Politicians with wide faces are seen as more corrupt, researchers have found.
In a series of studies 100 volunteers were shown pictures of 150 all white male politicians unknown to them, half convicted of corruption.
Participants were asked to rate each for how corruptible, dishonest, selfish, trustworthy and generous they seemed.
And they picked out bent politicians who had been convicted of corruption about 70 per cent of the time.
This is better than chance judgements, based on tests in which subjects knew nothing about the politicians or their careers, say psychologists.
The finding adds to previous studies suggesting men with wide faces have higher levels of testosterone – and are more likely to consider cheating on their partners.
Successful male business leaders have also been shown to have wider faces than average, making them appear more dominant, ambitious and powerful.
Co author of the study Chujun Lin, of the California Institute of Technology, said: “It might be difficult to understand why you can look at others’ faces and tell something about them.
“But there is no doubt 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.”
Co-author Professor Ralph Adolphs added: “As hypothesised, individual-level data showed face width had a significant effect on inferences of corruptibility; specifically, a participant perceived an official as more corruptible when his face was fat relative to when his face was slim.”
Researchers said face wideness – technically, the facial width-to-height ratio – has also been linked to aggression.
Men with wider faces have a greater tendency to be threatening towards others – and to be perceived as so.
But the latest findings are the first to show observers have a knack for picking out corrupt politicians based on just a portrait – and see them as more corruptible.
The researchers said it does not mean politicians who look corruptible are inherently worse than those who look honest.
There could be many explanations for the connection between facial appearance and corruption.
If a face conveys a sense of dishonesty, the politician might be offered bribes more often.
Another possibility is corruptible-looking politicians are not any more corruptible than honest-looking politicians.
But because of their looks they are more often suspected, investigated and convicted.
Ms Lin added: “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.”
Ms Lin also pointed out that the innocent politicians used in the study might not actually be that clean: “Maybe they just have not been caught.”
The findings published in Psychological Science might make you wonder how politicians get elected if just looking at their faces gives an impression of dishonesty.
Professor Adolphs explained that how we feel about political figures comes down to a lot more than just a face.
He said: “In the real world, you are not just seeing a photo of a politician. You are seeing them talk and move.
“Their face might make a first impression on you, but there are other factors that can come in and override that.”