Beauty May Not Lie in the Eye of the Beholder – It May Lie in Genetics

We currently live in a society that places a lot of value on how "beautiful" we are - and this can be hard to ignore. Dissatisfied with their external appearance, more individuals are opting to go down the route of cosmetic surgery. Statistics from the American Society of Plastic Surgeons show that almost 18 million people underwent surgical and minimal invasive cosmetic procedure in the United States in 2018 – almost a quarter of a million more people than in 2017.

In parallel, the cosmetics industry is one that continues to explosively grow, with the market value of skin care forecast to increase to $20.1 billion between 2014 and 2019.

Online, social media platforms have seen the rise of the "selfie", the Oxford Dictionaries Word of the Year 2013, and a common question thrown around is whether we are the most narcissistic generation to have ever lived.

Appearance can affect a variety of social aspects of our lives, from who we choose to have relationships with, our social exchanges, and even who we hire for positions of employment. 

Despite the importance humans and society appear to place on beauty, from a scientific perspective, we don't actually know a great deal about why certain faces appear "prettier" than others. Do genetics play a role here? 

Identifying parts of the genome associated with facial beauty

Researchers from the University of Wisconsin-Madison (UW) have conducted a genome wide association study (GWAS) to identify parts of the genome associated with facial beauty. "Facial beauty is a human trait that is of great interest worldwide. Previous studies provided evidence that attractiveness is genetically heritable, but no specific genetic variant has been identified for attractiveness", says Qiongshi Lu, Assistant Professor at UW and principal investigator of the study. "A map of genetic associations for attractiveness may allow us to quantitatively investigate the evolutionary reasons behind our preference for certain facial features."

The study, published in PLOS Genetics, used genetic information from a sample of 4,383 European individuals including both men and women. Volunteers were asked to score the sample's yearbook photos based on attractiveness, and the scores given to each person's photograph were analyzed with regards to their genetic information; "By linking each individual’s genetic information with his/her attractiveness rating, we were able to demonstrate the statistical associations between certain genetic variants and facial attractiveness" adds Lu.

GWAS studies are increasingly used in areas of science such as medicine, where researchers look for specific genetic variants that may increase disease susceptibility, for example. Nevertheless, their use in measuring attractiveness is a novel concept. The researchers have therefore created a study that spans two disciplines – genetics and sociology. Lu notes: Most sociological studies that focus on measuring attractiveness do not collect genetic data. The availability of matched genetic information and robustly measured attractiveness in our study cohort is the key to our success".

Genes related to attractiveness differ by sex

Several genes were identified across individuals that were measured as "attractive", and, interestingly, these genes differed across the sexes. In women, specific genetic variants associated with beauty were also related to genes impacting body mass. In contrast, variants associated to attractiveness in males were linked to genes affecting blood cholesterol levels.

"Our results suggest that there is not a ‘master gene’ with strong effect on facial attractiveness. Instead, attractiveness is most likely controlled by a large number of weak genetic associations with complex regulatory effects. That said, several relatively stronger association signals did show up in our analyses," Lu comments. 

So – beauty is not in the eye of the beholder?

"Our study suggests that sex-specificity is a central topic in the genetic basis of attractiveness - evidence seems to suggest that genetic association patterns differ between male and female raters. However, the associations we reported in this study were not driven by one or two raters’ particularly strong opinions. Instead, they seem to represent associations with the consensus among raters," says Lu.

The researchers are quick to note that there are limitations to the study that must be considered – principally, the fact that attractiveness is a subjective measure. "The perception of attractiveness depends on the study population, age group, cultural background, and many other factors. At this point, there is no evidence that findings in our study can be extrapolated to diverse populations or different age groups" Lu states.

In terms of next steps, Lu and team wish to expand their study to include more racially and ethnically diverse populations to investigate whether the same genetic variants are found to be associated with attractiveness. “Although genetic prediction of attractiveness may also be of interest, the current sample size used in our study is most likely insufficient for accurate prediction yet. Whether genetics can be used to predict beauty remains an open question" notes Lu.

Additionally, the researchers would like to use statistical genetic technology to investigate whether a causal link can be identified between specific variants and attractiveness. "These analyses will further improve our understanding of the complex relationship, maybe even causal relationship, between attractiveness and other sociological traits," Lu concludes.  

Reference: Hu et al. (2019). Genome-wide association study reveals sex-specific genetic architecture of facial attractiveness. PLOS Genetics. DOI: https://doi.org/10.1371/journal.pgen.1007973.