Over the past 30 years, research on attractiveness has paid too much attention to the importance of the face and body, ignoring the crucial role of smell and sound in the interaction between two people. As the international team of scientists led by Agata Groyecka points out: "Beauty is also in the nose and the ear of the beholder." The researchers carried out a review on attractiveness literature over the past 30 years. The results, published today in Frontiers in Psychology, found compelling evidence that olfactory and acoustic components played a major role in attractiveness, something that has been by and large missing in current research. "There was a disproportion in the literature regarding the role of different senses and different modalities in perceived attractiveness," said Groyecka, a Ph.D student in psychology at the University of Wroclaw in Poland. In the review, Groyecka and colleagues highlighted studies demonstrating that through the voice of an individual, we are able to determine dominance, cooperativeness, emotional state, and even the body size of the speaker. Likewise, studies also suggested that an individual's odor can be used to assess sex, fertility, diet, and genetic compatibility. In fact, odor allows us to recognize our own kin, a likely evolutionary mechanism to avoid inbreeding. "Most people might know what their type is — in terms of physical attractiveness — but they might not know what kinds of odors or voices they like," said Groyecka. "It is that feeling when you find someone attractive, but you're not really sure why you do." RELATED: Listening to Poetry Really Can Give You Chills and Goosebumps In the absence of visual cues, researchers found that an attractive voice or body odor elicited "prosocial behavior" and positive impressions among subjects. Actually, these elements can independently predict differences in reproductive and socioeconomic success. Another important finding was that when sight, smell, sound were evaluated simultaneously, the effect was synergistic — combined, they provided more information than any single element could individually. Combining an attractive face, for example, with an attractive voice or scent, resulted in a higher overall judgment of attractiveness than a single aspect could predict. What's more, the literature also showed a clear evolutionary significance of multisensory or multimodal indices being used to evaluate a potential partner, friend, or even colleague. The so-called redundant signal hypothesis, for example, proposes that if we pay attention to a series of traits in combination, or observe redundancy, we will have a better estimate of a person than if focusing on a single trait. The fitness indicator theory, likewise, posits that an individual's genetic quality is expressed through a combination of phenotypic traits. While the review came to some strong conclusions, it also portrayed the science of attractiveness as extremely complex. Women show a preference for an immediate level of overall masculinity, but were flexible in how they achieved this end. They may prefer less masculine bodies in men with more masculine voices, for example. And both sexes found the faces of people with similar genotypes to their own most attractive, though they preferred odors of those with dissimilar genotypes, suggesting that some level of genetic dissimilarity is preferable. RELATED: Moments of Epiphany Are Revealed in a Person's Eyes But those preferences, authors point out, could also shift in time and context. Visual and vocal characteristics of a partner tend to be more important to both sexes early in the relationship, whereas odor plays a more important role later, when partners are more intimate. Men place more value on women's bodies in the short-term and facial appearance in the long term, while such a difference among women's perceptions was less apparent. Groyecka admits that better understanding the intricacies of attraction will take greater research efforts, but she hopes that the review will inspire more scientists to integrate the neglected elements of smell and sound into their research. "Science is trying to find the most plausible models to understand nature — to understand how the world is constructed," said Groyecka. "We hope that researchers will study voice attractiveness without isolating it from faces or other features that people possess," she added. "In the real world, they do not exist in isolation."

Original article on Seeker.