To look trustworthy, put on a happy face

"You can influence to an extent how trustworthy others perceive you to be in a facial photo," says Jonathan Freeman, "but perceptions of your competence or ability are considerably less able to be changed." (Credit: iStockphoto)

We can alter our facial features to make us look more trustworthy, but not more competent.

A new study points to both the limits and potential we have in visually representing ourselves—in situations that include dating, career-networking sites, and social media posts.

“Our findings show that facial cues conveying trustworthiness are malleable while facial cues conveying competence and ability are significantly less so,” says Jonathan Freeman, assistant professor of psychology at New York University.

“The results suggest you can influence to an extent how trustworthy others perceive you to be in a facial photo, but perceptions of your competence or ability are considerably less able to be changed.”

Muscles and bones

The distinction is due to the fact that judgments of trustworthiness are based on the face’s dynamic musculature that can be slightly altered, with a neutral face resembling a happy expression likely to be seen as trustworthy and equally, a neutral face resembling an angry expression likely to be seen as untrustworthy—even when faces aren’t overtly smiling or angered.

But perceptions of ability are drawn from a face’s skeletal structure, which can’t be changed.

For the study, published in the journal Personality and Social Psychology Bulletin, researchers conducted four experiments in which female and male subjects examined both photos and computer-generated images of adult men.

In the first, subjects looked at five distinct photos of 10 adult men of different ethnicities. Here, subjects’ perceptions of trustworthiness of those pictured varied significantly, with happier-looking faces seen as more trustworthy and angrier-looking faces seen as more untrustworthy. However, the subjects’ perceptions of ability, or competence, remained static—judgments were the same no matter which photo of the individual was being judged.

Happy and angry expressions

A second experiment replicated the first, but here, subjects evaluated 40 computer-generated faces that slowly evolved from “slightly happy” to “slightly angry,” resulting in 20 different neutral instances of each individual face that slightly resembled a happy or angry expression.

As with the first experiment, the subjects’ perceptions of trustworthiness paralleled the emotion of the faces—the slightly happier the face appeared, the more likely he was seen to be trustworthy and vice versa for faces appearing slightly angrier. However, once again, perceptions of ability remained unchanged.

In the third experiment, the researchers implemented a real-world scenario. Here, subjects were shown an array of computer-generated faces and were asked one of two questions: which face they would choose to be their financial advisor (trustworthiness) and which they thought would be most likely to win a weightlifting competition (ability).

Under this condition, the subjects were significantly more likely to choose as their financial advisor the faces resembling more positive, or happy, expressions. By contrast, emotional resemblance made no difference in subjects’ selection of successful weightlifters; rather, they were more likely to choose faces with a particular form: those with a comparatively wider facial structure, which prior studies have associated with physical ability and testosterone.


In the fourth experiment, the researchers used a “reverse correlation” technique to uncover how subjects visually represent a trustworthy or competent face and how they visually represent the face of a trusted financial advisor or competent weightlifting champion. This technique allowed the researchers to determine which of all possible facial cues drive these distinct perceptions without specifying any cues in advance.

Here, resemblance to happy and angry expressions conveyed trustworthiness and was more prevalent in the faces of an imagined financial advisor while wider facial structure conveyed ability and was more prevalent in the faces of an imagined weightlifting champion.

These results confirmed the findings of the previous three experiments, further cementing the researchers’ conclusion that perceptions of trustworthiness are malleable while those for competence or ability are immutable.

Eric Hehman, an NYU postdoctoral researcher, and Jessica Flake, a doctoral candidate at University of Connecticut, are coauthors of the study.

Source: NYU