Height may contribute to attractiveness

Valentine’s Day is fast approaching, and while romantic comedies like to suggest that you may fall in love this Feb. 14 because of cosmic destiny, science begs to differ. A new study reveals that a human’s choice in romantic partner is influenced by their genes, including the genes that determine a person’s height. Throughout the last century, many studies concluded that height was a key factor in choosing a mate, but there was no explanation for this facet of sexual attraction. The study, published in Genome Biology, works to identify the physical traits that influence attraction, as well as the underlying aspect of genetic variation.

Using an analysis of the genotypes of more than 13,000 Caucasian heterosexual couples, researchers worked to uncover whether sexual attraction is caused by genes, and whether the genes that influence a person’s height also influence a person’s choice in partner.

The researchers found that there was a correlation between a person’s own height, as dictated by their genome, and their preference in a partner’s height. The study asserts that “the genetic correlation between height and the preference for a partner with similar height is 0.89, which indicates that genes affecting individual preferences for height and one’s own height are largely shared.” This indicates that a person’s genotype, or one’s genetic makeup, influences not only their phenotype, or their own physical appearance, but their preferences in the physical appearances of potential mates.

The scientists were then able to use “this observation to predict the height of the chosen partner from the person’s genotype with an accuracy equal to 64 percent of the theoretical maximum.” In other words, the researchers could accurately guess the height of a person’s chosen mate more than half the time through the person’s genotype and their own findings.

"Our genes drive our attraction for partners of similar height to ours, i.e. tall people pair with tall people. We found that 89 percent of the genetic variation affecting individual preferences for height and one's own height are shared, indicating that there's an innate preference for partners of similar height,” Albert Tenesa, a researcher from the University of Edinburgh and lead author of the study, said.

This revelation that humans choose their partners partially because of genes dictating their height may lead to larger scientific implications. While some may say that fate or destiny rule a person’s love life, human genes influencing the partner selection process is indicative of the greater biological phenomena of assortative mating at work.

Assortative mating is a mating pattern in which people with certain physical characteristics have a higher chance to choose each other as partners than should be expected. It is the “like marries like” effect: blondes have a higher chance of partnering off with other blondes, brown eyed people have a higher chance of mating with brown eyed people, people of the same body size have a higher chance of marrying and so on. Assortative mating “plays a crucial role in shaping the genome structure of the population,” as the study says, and leaves a great impact on variation within the human gene pool. These findings offer insight on how assortative mating operates on a genotype level and what that means for the future of humanity’s genes.

The study also says that its findings offer “the opportunity to search for the genetic variants and mechanisms that determine individual preferences for mate height, as well as other traits that govern human sexual attraction.” Human sexual attraction and the mechanisms that trigger it are still regarded largely as a scientific mystery, and this study could lead to more insight into both this and the mechanisms that drive human genetic variation.

Whether you believe in the logic of romantic comedies or hard science, this Valentine’s Day, there is no denying that assortative mating, and subsequently these new findings on genotype, phenotype, physical attraction and height all play an interesting role in human romance and sexual attraction.