Researchers at the University of Wisconsin at Madison have a handy database for finding the genetic makeup of attractiveness - the Wisconsin Longitudinal Study (WLS). It started in 1957 and was attended by several thousand fresh college graduates of European descent, from whom DNA samples were collected.
60 years later, scientists returned to the WLS data to apply new genome-wide sequencing techniques to it. The researchers matched people with the same birth year as WLS members and asked them to rate the visual attractiveness of WLS members based on photos in school albums. Based on the assessments of 12 people (6 men and 6 women), the researchers calculated the indicator of attractiveness. And then they looked for correlations between the levels of attractiveness (for men, for women, and for all together) and the presence of any single nucleotide polymorphisms ("single letter" differences) in the genome of the participants.
Looking ahead, we will say that no single “beauty gene” that is uniquely associated with attractiveness has been found. However, the authors of the study did not expect this, since the appearance is a polygenic trait, which also depends on many environmental factors. Nevertheless, it was possible to trace some correlations.
The attractiveness of any people to any evaluator turned out to be associated with three sections of non-coding DNA. The closest genes to these are genes that correlate with body mass index, hip circumference and face shape. In addition, women preferred people with polymorphism, probably related to skin pigmentation. And for men, no unambiguous links between preference and polymorphisms could be identified.
The researchers then tested the association of "attractive" polymorphisms with various other complex traits. It turned out that polymorphisms “attractive” for men are often found in the genome at the same time as others associated with skin pigmentation. At the same time, women who “liked” somehow correlate with others that determine hair color.
Finally, the authors of the project tried to find the relationship between attractiveness and other physiological parameters, without the mediation of genes. At the same time, the attractiveness of women for men was negatively associated with body mass index, and the attractiveness of men for women grew along with the amount of cholesterol in the blood. This may be due to the production of male sex hormones, for which cholesterol is a precursor.
Thus, the Wisconsin researchers have taken another small step forward towards deciphering the human concept of beauty. Let now these are separate "letters" in the genome, only remotely correlating with specific parameters, but even on their basis, certain conclusions can be drawn. For example, most of the identified connections indicate either the amount of fat in the body, or the color of integumentary tissues, but there are practically no connections with the shape of individual parts of the face or the color of the eyes. In addition, the authors of the project note that in almost all analyzes that they conducted, the results were significantly dependent on gender (both the evaluator and the person being evaluated). This may indicate that the criteria of attractiveness for men and women are different.
However, at the end of the article, the authors pay great attention to the limitations of their study: they consider their sample rather modest and propose to test their results on a larger number of participants. In addition, all WLS subjects had Caucasian appearance, and it is possible that scientists with a different ethnicity will be able to get different results. Finally, the photographs of the members were taken more than 60 years ago, and since then, the criteria for beauty may have changed.
