The Chemistry of Love

We’ve all heard our friends talk about chemistry and connections. Rock stars sing about the “chemicals between us” and movies depict racing hearts, sweaty palms, and love at first sight. Have you wondered where all of these scientific, chemical, and physiological terms and ideas manifest in relation to love and attraction? It might surprise you to know just how much of your relationship is invested in hormones.

Why do we even have “Chemistry” with other people?

Long ago in our evolutionary history, before courtships and ‘til death do us part were the norms, our ancestors needed encouragement to reproduce and raise children. In response to the need to continue the species, humans developed a few romantic functions to increase the desire to find mates and create family units. The first basic instinct, which most animals have, was the sex drive, or the need to reproduce; this created a desire to look for partners. Romantic love, or the instant chemistry you experience from meeting a great partner, then developed to keep our minds on only one mate at a time; this helped and helps us conserves both time and energy. Last, we developed a sense of attachment. Attachments and bonding create the desire for long-term partners, allowing us to build a secure family unit and raise children.

Why does love feel the way that it does?

The feelings that we associate with falling in love, especially the initial and highly romantic and passionate stages of the relationship, are the body’s response to three major chemicals. These chemicals affect some of the brain’s powerful pleasure circuits, triggering feelings of euphoria and focused attention on your partner; in fact, the initial romantic feelings work something like a drug.

Dopamine is the most prevalent chemical in this love reaction. Dopamine is considered the “pleasure chemical” and is responsible for our feelings of happiness and physical responses to being in our partner’s presence. Combined with phenylethylamine, it creates the racing heart, flushed skin, and sweaty palms that might let you know that you have something of a crush on the other person. Norepinephrine is another chemical involved, and functions similarly to adrenaline. This chemical creates the rush of excitement that we feel when we are around our partner. Together with dopamine and phenylethylamine, we feel intense energy, sleeplessness, craving, and much focused attention.

We can also thank dopamine for our attention to our partners. When we’re feeling romantic love and attraction towards our partner, we experience an increased blood flow in areas of the brain with high concentrations of dopamine receptors. Our brain begins to focus on our partner, acting as though we are addicted to the person and our body’s reaction to them. Combined with norepinephrine, we begin to focus our attention on our partners; our short-term memory increases and we engage in goal-oriented behavior, generally focused on being with our partner.

Some researchers suggest that serotonin is also involved with feelings of love. During the attraction or early stages of romantic love, we have lower levels of serotonin, which causes us to behave differently. In fact, the serotonin levels of people in love are similar to those with obsessive-compulsive disorder; this explains why some of us seem to obsess over our partners.

What comes next?

After an initial courtship, filled with racing pulses and days of excitement, we begin the process of chemical bonding. As we commit sexual acts with our partner, our body begins releasing chemicals that encourage bonding or feelings of deeper attachment. The hormone oxytocin, which is released during sex creates a deep attachment; this feeling increases with each release. Vasopressin, another chemical that is associated with attachment and the formation of long-term relationships, is also released. When combined, oxytocin and vasopressin begin to interfere with the dopamine and norepinephrine; this can leave partners feeling less passion, but higher levels of attachment.

Why don’t we keep these same feelings of love and attraction throughout the relationship?

The longer we stay with a single partner, the more a relationship matures. Instead of that rush of excitement we used to feel just thinking about our partner, we might feel a little complacent. They might no longer be the image of perfection that they once were, and we can sometimes feel annoyed with them.

The giddy excitement of attraction is associated with the very early stages of a relationship; once they are gone, the relationship has either dissolved, or has matured into a long-term relationship. In fact, after two or three years, researchers find almost no sign of the initial dopamine and norepinephrine reactions.

A long-term relationship is based on the attachment formed during the early stages of a physical relationship. Other chemicals, the oxytocin and vasopressin, are hard at work produce feelings of satisfaction and attachment when you are with your partner; these strengthen as you engage in healthy, physical relationships. Endorphins also work to keep you feeling secure in your relationship and happy with your partner.

Doesn’t the idea of science and chemicals take the romance out of Romance?

Some people might find the idea of evolution in love somewhat cynical, but scientific theory and hypotheses haven’t taken the romance out of relationships. Think about this: Humans are one of the only species on the planet that was designed to love. In fact, we just proved that love wasn’t created by men, or imagined for the sake of medieval poetry. We have evidence of love in more than 150 societies, and can trace evidence of love poetry and proclamations back as far as 4,000 years ago. We actually have proof that love exists.