Love, Decoded

Why are people attracted to specific traits in romantic partners? How can someone garnish all their dishes with cilantro and someone else recoil at the thought? What makes an individual reach for sweet snacks instead of salty ones?

 The mystery behind why we love what we love has fascinated humanity for millennia.

But even love – that intangible emotion long contemplated by philosophers, artists, poets, and head-over-heels teenagers – is not impervious to the reach of DNA. In fact, research shows that genetics can influence our preferences and tastes.

Birds of a Feather

It turns out there might be some scientific proof to the adage “birds of a feather flock together,” at least when it comes to mate preference.

A study published in Nature Human Behavior identified genetic evidence for assortative mating, defined as the tendency to select and mate with partners who are similar to us.

 Researchers at the University of Queensland, the University of North Carolina, 23andMe, and other institutions, looked at two specific traits in couples: height and body mass index (BMI).  

They used data from more than 24,000 couples, including 11,908 consenting couples from 23andMe, and compared an individual’s genetically predicted height and BMI to those of their partner.

The study found a strong correlation between people’s genetic predisposition for height and their partner’s actual height. A weaker but still statistically significant correlation was also found between people’s genes for BMI and the actual BMI of their partners.

Pass the Salt… or the Sugar

Picture your perfect snack. Is it sweet – a bowl of ice cream, or maybe a cookie? Or is it salty (think: popcorn or chips)?

Genetics may influence your choice by impacting how your brain identifies and responds to tastes.

 It all starts with a single bite. When food enters your mouth, your taste buds get to work – sending signals to two different brain areas. These regions help you identify and decide if you like a flavor.

Scientists from 23andMe have identified 43 genetic markers associated with a preference for salty or sweet foods. 

 Several of these markers are found near genes involved in brain development and function. And two are located in genes associated with food metabolism and body mass, including the FTO gene, which has been linked to obesity.

The Great Cilantro Divide

Add cilantro (also known as coriander) to the list of topics you shouldn’t bring up at the dinner table. Like politics and religion, this green, leafy herb elicits surprisingly strong reactions. Some hate it and swear it tastes like soap. Others love it and can’t imagine a dish without it. 

What makes this herb so polarizing? Genetics offers a clue. 23andMe researchers found two genetic markers associated with cilantro aversion located near a cluster of olfactory receptor genes. Some of these receptors help us perceive aldehydes, chemical compounds that contribute to cilantro’s “soapy” scent.

Culture and environment can also influence cilantro preference. According to a 23andMe study, only 3-7 percent of those who identify as South Asian, Latino, or Middle Eastern dislike the herb compared to 14-21 percent of people of East Asian, African, or European ancestry. 

Researchers posit that this difference could be partially due to the ubiquity of cilantro in various regional cuisines, which results in frequent exposure to the herb.

In light of these research findings, perhaps we can offer an addition to this well-known quote by the Sufi mystic and poet Rumi: “Only Love… [and DNA] can explain the mysteries of Love.”

Happy Valentine’s Day!