Faces and bodies send matching signals of attractiveness, but voices tell a different story

Human judgments of potential partners often rely on a blend of physical features, including faces, bodies, and voices. A recent study published in Evolution and Human Behavior reveals that while face and body attractiveness often align, voice cues provide independent insights into an individual's traits. These findings suggest that our physical appearance communicates a mix of shared and independent information to observers.

Evolutionary psychology posits that physical traits signal genetic quality and health to potential mates or rivals. During partner-seeking, individuals assess attractiveness to gauge underlying fitness, while competing against rivals may evaluate physical dominance to determine formidability. Researchers investigate how these visual and vocal cues combine to form an overall impression of an individual.

One major hypothesis, the "one ornament hypothesis," suggests that different physical traits, like face and body, are governed by the same biological factors, acting as a unified signal of health or genetic fitness. Conversely, the "multiple messages hypothesis" argues that different body parts convey distinct pieces of information.

For instance, a face may signal immune system strength, while a voice could indicate physical dominance.

Researchers hypothesize that sex hormones like testosterone and estradiol drive the coordinated development of these physical traits. Higher testosterone in men and higher estradiol in women are believed to influence traits perceived as attractive, healthy, or dominant. To test these hypotheses, a research team led by Tobias L. Kordsmeyer from the University of Goettingen conducted an experiment involving 165 men and 155 women.

They collected standardized facial photographs, three-dimensional body scans, and voice recordings from each participant. Facial photos featured neutral expressions against a white background, while body scans were gender-neutral digital models without skin texture for focus on shape and proportions. Voice samples were collected using a standardized text for females and positive life aspects for males.

The final evaluation involved 400 independent raters who assessed attractiveness, health, and physical dominance using standardized scales while avoiding cross-trait influence.

The results showed strong correlations between face and body attractiveness and health ratings, supporting the one ornament hypothesis. Observers seemed to interpret facial and bodily cues redundantly, perceiving shared information about the individual's physical condition. Sex hormone levels measured in saliva and hair samples from participants also correlated with these perceptions, particularly in men, where reactive testosterone after a competitive task influenced dominance ratings.

In contrast, voice ratings showed little to no association with face or body attractiveness, supporting the multiple messages hypothesis. This suggests that while faces and bodies share redundant information, voice remains a distinct channel of communication offering independent cues about an individual's traits.