Unattractive faces may get a break: Study reveals “ugly leniency effect” in guilt judgments

A surprising study published in Psychiatry, Psychology and Law suggests that when people make judgments about a defendant’s guilt in a case where physical appearance could plausibly play a role—such as a blind date swindle—they tend to be more lenient toward unattractive faces. This finding, which the researchers describe as an “ugly leniency effect,” challenges the assumption that attractive individuals always receive more favorable treatment.

The researchers set out to understand how first impressions based on facial appearance might affect decisions of guilt or innocence in legal cases. They were particularly interested in the roles of facial attractiveness and trustworthiness when a defendant’s appearance could be used as an advantage in committing a crime.

Previous work had shown that attractive people are often assumed to possess positive traits, while unattractive individuals may be unfairly judged harshly. However, the connection between attractiveness and guilt had not been fully explored, especially in cases where the appearance itself might help the crime succeed.

“I was really interested in exploring the consequences of facial biases in the legal field,” said study author Antonio Olivera-La Rosa, a full professor at Luis Amigó Catholic University in Medellín. “I feel that, among all the areas susceptible to experiencing the consequences of facial biases, the legal field is one that requires the most attention. It is not difficult to understand why. Personally, I think it’s important to integrate our knowledge of human cognition to human practices and institutions.”

For their study, the researchers recruited 128 participants through email and social media. The participants were primarily from Colombia, with a smaller number from Spain and Peru. The study was conducted online, and all participants provided their consent before starting.

First, participants completed a questionnaire to collect demographic information, such as age, gender, and education level. They also completed the Rational Experiential Inventory, a tool used to measure individual differences in thinking styles. This inventory assesses the degree to which individuals rely on rational thinking (analytical, intentional) versus experiential thinking (intuitive, automatic).

Next, participants were randomly assigned to one of two groups: a high time pressure condition or a low time pressure condition. In the high time pressure condition, participants were instructed to make their judgments as quickly as possible. In the low time pressure condition, they were given as much time as they needed.

All participants were then presented with a hypothetical scenario: a blind date swindle case. They were asked to imagine themselves as judges and to assess the guilt or innocence of nine male faces. The faces were selected from the Chicago Face Database and categorized into three levels of attractiveness: unattractive, neutral, and attractive. Importantly, all faces had consistent and average levels of perceived trustworthiness. Participants were asked to give their first impression of whether or not each face looked guilty. After each judgment, they rated how certain they were about their decision on a seven-point scale.

The results of the study revealed a significant effect of facial attractiveness on guilt judgments. Specifically, participants were more likely to judge unattractive faces as innocent compared to both neutral and attractive faces. This finding suggests that an “ugly leniency effect” was at play, where less attractive individuals were given the benefit of the doubt.

The researchers found that time pressure did not significantly influence the relationship between facial attractiveness and guilt judgments. Whether participants were under time constraints or not, the ugly leniency effect persisted.

They also found that individual differences in thinking styles, as measured by the Rational Experiential Inventory, did not significantly impact guilt judgments. Participants who were more inclined toward rational thinking were just as likely to exhibit the ugly leniency effect as those who were more inclined toward experiential thinking.

The study further explored participants’ beliefs about the role of physical appearance in the crime scenario. Researchers found that participants generally believed that the defendant’s appearance could influence the success or failure of the swindle. Additionally, a majority of participants acknowledged that the attractiveness or unattractiveness of the faces may have influenced their responses.

“Our results provide valuable insights by demonstrating that, under specific conditions, unattractive faces can reduce guilt perception,” Olivera-La Rosa told PsyPost. “This evidence could enhance awareness of how implicit bias influences legal decisions, potentially reducing the skepticism many judges express towards such extralegal factors. While the legal system is traditionally grounded in rationality, it is not immune to the influence of facial biases.”

But there is an important caveat to consider: the study focused on a specific type of crime—a blind date swindle. This focus limits the generalizability of the findings to other types of offenses.

“The purpose of our study was to gain a deeper insight into the intuitive nature of initial judgments about guilt or innocence,” Olivera-La Rosa explained. “As such, our findings should not be seen as proof that individuals with unattractive (yet moderately trustworthy) faces are necessarily more likely to receive lenient judicial sentences. Indeed, facial bias may be reduced or even diminished during the examination of evidence.”

Future research could examine the effects of facial attractiveness on guilt judgments in a wider range of criminal scenarios, using both male and female faces. The researchers aim to further explore how factors such as facial appearance can unconsciously influence jurors’ decisions and to develop methods for reducing these biases within the legal system.

“The progress made within the interdisciplinary field known as neurolaw has led to greater interest in studying these issues from perspectives that incorporate cognitive sciences,” Olivera-La Rosa said. “Although it may sound obvious, jurors are still people, which means that they can be susceptible to facial bias. More research is definitely needed, along with identifying the best ways to incorporate these findings into traditional legal systems.”

The study, “When being unattractive is an advantage: effects of face perception on intuitive culpability judgments,” was authored by Antonio Olivera-La Rosa, Luis D. Ayala, and Ricardo M. Tamayo.