A new study published in Scientific Reports explored the relationship between immune system functioning and perceived attractiveness. In contrast to previous studies, the results indicate no relationship between the two variables. Although it may be true that immune system functioning plays a role in whom we find attractive, this study has determined that evidence of a robust immune response cannot be found in the face.
Evolutionary psychology has long been attempting to understand human attraction through a reproductive lens. Humans may like symmetrical faces because it is an indicator of good genes. Full lips may be a marker of fertility, and bright eyes and clear skin may indicate robust health. Research has also tried to connect attractive facial features to immune system strength. The methods used in these endeavors and the findings have not been consistent.
To correct these problems, Žaneta Pátková and colleagues designed a study using direct measures of immune system functioning. The research team recruited 52 males in their early 20s and activated their immune systems by giving vaccinations for hepatitis and meningococcus. Blood samples were collected before and after vaccination, and the following levels were measured: cytokines, interleukin-1 receptor antagonist, tumor necrosis factor-alpha, C-reactive protein, cortisol, testosterone, and estradiol.
The participants were also assessed for facial attractiveness using over 100 individuals who were asked to rate photographs of the male participants using a scale of 1 (not at all attractive) to 7 (extremely attractive). The women also rated the men on how healthy they appeared to be, again on a one to seven scale. Each male face was rated more than once, and data analysis confirmed the reliability of the attractiveness ratings.
Their findings indicated that facial attractiveness ratings and perceptions of health were strongly correlated, and this turned out to be the only meaningful relationship found. As for perceived attractiveness and immune system functioning, no relationship was found. Those who were identified by raters as attractive and healthy did not have corresponding robust immune responses.
Measurements of testosterone and cortisol were also taken to determine if they were related to immune system functioning, as these factors have been implicated in perceived attractiveness. This study found no relationship between testosterone, immune system functioning, or perceived attractiveness.
This was a surprising finding as previous research has found higher testosterone levels to be related to higher scores on measures of attractiveness. Additionally, individuals with high cortisol were perceived as slightly less attractive than those with less.
The research team suggested some possible explanations for their findings. First, they acknowledged that the small sample size and a more representative sample may have yielded different results.
Second, the study only utilized young men, and it could be as individuals age that, the relationship between immune system functioning and perceptions of attractiveness becomes stronger. In addition, female or non-binary individuals were not studied.
This research contributes to understanding what components may or may not contribute to human perceptions of attractiveness. According to Pátková and team, “Despite some limitations, we believe that our study is a valuable contribution to research on the role of visual cues in assessments of functioning of the immune systems of individuals and that it can serve as an entry for future meta-analysis aimed at disentangling the conflicting results of various existing studies.”
The study, “Attractive and healthy‐looking male faces do not show higher immunoreactivity,” was authored by Žaneta Pátková, Dagmar Schwambergová, JitkaTřebická Fialová, Vít Třebický, David Stella, Karel Kleisner and Jan Havlíček.