Perceptions of beauty are 50% individual

What we find aesthetically pleasing depends largely on previous personal experience, according to research published in Current Biology.

Perceptions of beauty depend largely on unique individual experiences.

While people disagree on which celebrity or friend is better looking, it now seems that the decision is largely individual. Our opinions are mostly the result of personal experiences that are unique to each person; they may differ sharply even between identical twins.

Prior studies of twins and families have shown that most human traits, from personality to ability to interests, are largely passed down genetically from one generation to the next. Even the ability to recognize faces has been found to have a genetic link.

The researchers from Massachusetts General Hospital and Harvard University, and from Wellesley College - all in Massachusetts - worked as joint leaders of a project to investigate the question: to what degree is beauty really in the eye of the beholder?

They also wanted to know what sorts of factors may contribute to "the eye of the beholder," and where disagreements on facial attractiveness come from.

They started from the premise that some aspects of attractiveness are universal, for example, symmetry in a face or averageness, and some may be genetically coded.

They now estimate that beyond that, an individual will be approximately 50% in agreement and 50% in disagreement with others about what is beautiful.

35,000 participants surveyed in online test

To find out more, they set up an online test on their website, which was visited by over 35,000 participants. In the test, the participants expressed preferences for 50 different male and female faces by rating their attractiveness on a scale of 1-7.

The program calculated a score for each participant that would reflect how similar his or her preferences were to those of the average person.

For example, if the average score was 0.42, someone with a score of 0.8 would have preferences closer to those of the average person; in other words, their preferences were more typical.

If someone scored a lower-than-average score, such as 0.2, this would indicate that their preferences were less similar to those of the average person; in other words, their preferences were less typical or more unique.The insights gained from this test were used to develop a highly efficient and effective test of the uniqueness of an individual's face preferences.

Even identical twins disagree on what is beautiful

The preferences of 547 pairs of identical twin and 214 pairs of same-sex, non-identical twins were tested by having them rate the attractiveness of 200 faces.

Comparing between identical and nonidentical twins enabled the team to estimate the relative contribution of genes and environment to face preferences.

Participants agreed substantially about which faces were more and less attractive. However, they also found that average aesthetic preferences can mask substantial individual differences.

Selecting two participants at random produced an average of only 48% agreement (and 52% disagreement) in face preferences, even after adjusting for self-inconsistency.

The researchers conclude that the uniqueness of an individual's facial preferences is mostly based on experiences, not genes, and those experiences are highly specific to each individual.

"The types of environments that are important are not those that are shared by those who grow up in the same family, but are much more subtle and individual, potentially including things such as one's unique, highly personal experiences with friends or peers, as well as social and popular media."

In other words, it is not education, economic standing or who lived next door that makes the difference. 

Perceptions of beauty are apparently closely related to the experiences that are truly unique to each individual: faces the person has seen, the unique social interactions each individual has every day, perhaps even the face of one's first boyfriend or girlfriend.

The researchers say that the impact of personal experience on individual face preferences "provides a novel window into the evolution and architecture of the social brain."

They suggest that future studies could look more closely at which aspects of the environment are most significant in shaping preferences for certain faces and for understanding what influences preferences for other things, such as art, music or pets.

References:

1.  Individual aesthetic preferences for faces are shaped mostly by environments, not genes, Laura Germine et al., Current Biology, doi.org/10.1016/j.cub.2015.08.048, published 1 October 2015, abstract.
2.  Cell Press news release, accessed 1 October 2015.