The Science of Love

Illustration by Alyssa Long | The Bottom Line

Jessica Gang
Opinions Editor

Picture this: you’re walking through the Arbor on a sunny Santa Barbara day, when all of a sudden you see them: the person of your dreams! You might be separated by throngs of harried-looking students just trying to get to class, but chances are, your palms just started sweating, your mouth felt dry and, dare I say it? Your heart skipped a beat. Believe it or not, these are all biological reactions. Forget an achy-breaky heart, because as it turns out, you’ve got love on the brain.

For centuries, scientists, philosophers, artists, and writers (along with pretty much everyone else) thought that feelings of love, lust, and other emotions were the results of varying levels of four “humors” in the body. The theory behind these humorsblack bile, yellow bile, phlegm, and sanguine (blood) — was originally developed by Hippocrates and his followers, and eventually became the dominant theory of Western medicine until the Renaissance.

When the humors were in balance, good health and a calm temperament prevailed. When a person’s humors fell out of balance, however, ill-temper and unhappiness prevailed. If a person experienced feelings of sadness and depression, for example, it was assumed that these feelings were the result of a predominance of black bile. Similarly, an excess of yellow bile would make someone angry or impulsive.

It was only recently as the field of modern medicine took shape that scientists discovered that love and its related emotions are the result of chemical and hormonal changes in the brain. According to scientific experts, love can be broken down into three basic emotions: lust, attraction, and long-lasting attachment.

Lust is ruled by testosterone and estrogen, which are secreted from the testes and ovaries. Attraction, occasionally confused with lust, has notable differences. You can lust after someone and also be attracted to them, but this certainly isn’t mutually exclusive. In its most basic form, attraction is just interest. It’s possible to be attracted to the colors, flavors, and physical attributes of a delicious sandwich without wanting to see what it looks like without its bread on!

High levels of dopamine and norepinephrine are released by the hypothalamus when we experience attraction. That explains the giddiness and the euphoria that you feel when you first fall in love. Attraction also leads to a decrease in the production of serotonin, a hormone involved in controlling appetite and mood, making it possible to be so in love that you can’t eat and have difficulty sleeping.

Long-term attachment is primarily dictated by the hormones oxytocin and vasopressin. Oxytocin, also known as the “cuddle hormone,” is released in large quantities when humans participate in activities that relate closely to bonding things like having sex, breastfeeding, and giving birth.

But what about heartbreak? Is there any biological explanation for why love ends and why it hurts when it does? Well, we might have to ask pop singer Kesha about that one, because apparently, your love really can be my drug.

In the same way that an addict suffers as the result of drug withdrawal, when the brain suddenly stops pumping out the elevated levels of dopamine and oxytocin, we experience similar negative effects. Studies have shown that breakups can actually affect the area of the brain that processes physical pain.

Surprisingly, the key to understanding heartbreak might actually lie in an unexpected source: the prairie vole. Prairie voles (also known by the dubiously affectionate nickname “potato chips of the prairie”) are the only breed of 155 species of vole to pursue monogamous relationships. This is especially startling given that their biological cousins, the meadow voles, are fairly promiscuous.

Prairie vole relationships mirror human relationships in unexpectedly similar ways. Prairie voles meet, fall in love, and have the occasional tryst with another partner, but for the most part, seem to be affectionate partners and parents. Interestingly, when one-half of a prairie vole relationship dies, their partner rarely seeks another replacement and tends to exhibit characteristics in line with mourning.  

In a test conducted by Oliver Bosch, a neurobiologist who studies vole separation, when dropped into water, prairie voles separated from their brothers paddled maniacally, a behavior characteristic of the animal drive for survival. Voles who had been separated from their female mates, however, simply “floated listlessly.”

Much of this unprecedented monogamy can be attributed to the fact that prairie voles have a denser field of receptors for oxytocin and vasopressin than their meadow vole counterparts. Dr. Larry Young, a neurobiology professor at Emory University, avidly studies prairie voles in the hopes of one day helping humans to better cope with the loss of loved ones.

For now, all we know is that being separated from someone you love hurts. However, sometimes it helps to understand that our feelings are all part of the way our bodies are built.

We might never have a concrete explanation for the complicated emotions that come with romantic loss, but one thing’s for sure: loss is a necessary part of falling in love, which in turn, is just one of many parts of the big, wonderful machine that is the brain. Lust, attraction, and attachment are necessary parts of helping us understand so much of lifefrom what it means to love your friends and family to what it means to really fully appreciate the beauty of a good sandwich.

So the next time you see someone with the best smile or the cutest outfit you’ve ever seen, you might want to consider taking a swig of water and wiping off your sweaty hands, because you owe it to your brain to go over and introduce yourself! Who knows what might happen next?