New research indicates that facial attractiveness is a signal of healthy immune function

Can you tell someone’s health by looking at their face? A study published in Proceedings of the Royal Society B suggests that there is a relationship between people’s immune functions and their perceived facial attractiveness.

There are facial traits that are seen as being more attractive, regardless of culture, race, age, or background, such as clear skin and red lips. Evolutionary psychologists have linked the cross-cultural preference for the features to adaptive mate selection, as they may signal health and immune function. Though this intuitively makes sense, research on the topic has been lacking.

“I became interested in this topic because, within academia, there has always been an assumption that facial attractiveness is a signal of good immune function, but no one has ever directly tested this hypothesis and found evidence to support it,” explained study author Summer Mengelkoch, a graduate researcher at Texas Christian University.

“Previous work has been inconclusive, and relied upon indirect proxies of immune function (like health or longevity) as opposed to directly testing relationships between attractiveness and immune function. I wanted to conduct a critical test of this hypothesis to see if I could find evidence to support it or not!”

Mengelkoch and colleagues used 159 university students in Texas as participants in Phase I of this research. They were screened to ensure a lack of obesity, chronic illness, mental illness, and hormonal medication. Women participated during the early follicular stage of their menstrual cycle to control for sex hormones. Participants were photographed without any makeup and while making a neutral expression. Their weight, height, and blood sample were then taken. Blood work was completed, and participants completed questionnaires. In Phase II of the study, 492 participants rated the facial attractiveness of the subjects from Phase I.

Results showed that there is a relationship between immune function and facial attractiveness, specifically the aspect of the immune system that deals with bacterial threats. There are gender differences seen in this relationship, with certain measures of immune function, such as NK cells, as being perceived in opposite ways, specifically women with lower levels were seen as more attractive but men with higher levels were judged as more attractive. This study linked attractiveness with immune function but not with any acute measures of health. This may suggest that the adaptive measure is that people gravitate towards partners who could fight off illness rather than simply preventing contact with someone who is sick.

“Generally, people are told that caring about attractiveness, or facial beauty, makes someone shallow or superficial. But these results indicate that caring about the facial attractiveness of a romantic partner might be about more than just looks, it also might help you to select healthy partners,” Mengelkoch told PsyPost.

This study aimed to explore the relationship between health and perceived attractiveness. Despite the great strides made, it also has some limitations. Firstly, which facial features specifically are associated with immune function is out of the scope of this research. In addition, other aspects of one’s appearance, such as body type, could be significant on this topic, though it was not considered in this study. Lastly, this study excluded people in Phase I who had chronic physical or mental illnesses, and these results could change with a larger, more diverse subject pool.

“We tested relationships between facial attractiveness and immune function in a sample of relatively healthy college students, with limited diversity,” Mengelkoch said. “This should be tested in broader populations. Additionally, while we utilized a much larger number of immune measures than has been used in previous research on this topic, there are still many other facets of immune function which have yet to be explored. I would love to do a live immune challenge study, to investigate how a person’s attractiveness relates to their whole immune system’s ability to combat a live pathogenic threat.”

The study, “More than just a pretty face? The relationship between immune function and perceived facial attractiveness“, was authored by Summer Mengelkoch, Jeff Gassen, Marjorie L. Prokosch, Gary W. Boehm, and Sarah E. Hill.