To what degree is an individual's height choice in a partner genetically determined?

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With Valentine’s Day just around the corner, we might start to think about what attracts us most to our partners: their eyes, their laugh, the clothes they wear? There are a multitude of reasons for why we might be attracted to someone, but what about height?  Do you find yourself more attracted to individuals of a similar height to yourself?

Of all the human traits, height has long been known to be an important factor in determining who we choose to date. A vast array of studies has shown that individuals are drawn to those of a similar height, but what continues to elude us is whether this trend of choosing a partner phenotypically similar to ourselves is environmentally or genetically determined. According to a study recently published in Genome Biology, our genes may have an important influence over who we are attracted to.

What was done and what did the researchers find?

By taking height as a model trait for attractiveness, researchers from the University of Edinburgh estimated to what degree individuals’ height choice in their partner is genetically determined, as well as how far genes that contribute to one’s height are the same as those that affect individual preference for mate’s height.

Our genes may largely influence our preference for a partner of a certain height, and as it turns out, this is most likely to be a height that is similar to our own.

They reported that following an extensive study of just over 13,000 genotyped couples, 4.1% of the variation in their choice of mate was predetermined by their genotype. In other words, our genes may largely influence our preference for a partner of a certain height, and as it turns out, this is most likely to be a height that is similar to our own.

A strong positive correlation between an individuals’ own height and the preference for a partner to be of similar height was recorded – indicating that the genes that influence our own height and a preference for our partners’ height may be largely shared.

It was also noted that among a dataset of over 15,000 individuals, the genotype of an individual predicted their partners’ height with 13% accuracy. This suggests that there is a significant genetic component for choice of mate’s height in humans.

What could this mean?

For almost a century, studies have estimated that height is 80-90% heritable. However, when delving deeper into the genomes of individuals it is very difficult to identify genetic variants that determine height. This is known as ‘missing heritability’.

The study provides new insight into the mechanisms that govern mate choice in humans, and clearly demonstrates that genetic variation influences our choice of partner.

Theoretical predictions suggest that around 5% of the heritability of height is due to the positive covariance between allelic effects at different loci, which is caused by assortative mating.

This ultimately means that when we choose to date an individual of similar height to ourselves, we may be contributing substantially to the missing heritability of height – a debate that continues to puzzle researchers.

Mate choice in humans

The study provides new insight into the mechanisms that govern mate choice in humans, and clearly demonstrates that genetic variation influences our choice of partner. So when you start to think about what it is that has brought you together with your partner, you might have your genes to thank (or blame)!