The Science of Love 101


Scientists have cracked the code for this once elusive concept.

The science of love has been explored extensively. Research strongly points to the role of neurochemistry; that is, the role of certain chemicals in our brain and body, including hormones and neurotransmitters. There are two main forces in love: attraction and attachment. Each involves a different cocktail of chemicals. Curious about which areas of the brain light up when you are in love? Also, what's exactly in that delicate cocktail of chemicals responsible for the different stages of love?

The Brain

The brain is split into two hemispheres: the left and the right. Each hemisphere has different functions. The right hemisphere is responsible for feelings and holistic thinking. The left hemisphere is more concerned with planning and analysis. The right hemisphere, scientists argue, is the hemisphere of love.

Brain-imaging studies have established that two primary areas of the brain become active when you're in love. These are the foci in the media insula, which is classically associated with instinct, and the anterior cingulate cortex, which is most known for its ability to produce feelings of euphoria. Together, these brain areas make being in love feel like happiest and most natural thing in the world.

In the early stages of love, the caudate nucleus and the ventral tegmental areas become active. This is because these areas become overrun with dopamine, "the love chemical," which provides the addictive component of love. This is part of what often makes it very difficult to leave someone who is wrong for us.

The Neurochemistry of Attraction

This early stage of love is full of lust, desire, and infatuation. Lust is regulated by the primary sex hormones, testosterone and estrogen. Desire is a whole body experience that is influenced by adrenaline (also known as epinephrine). This is the chemical released during the fight or flight response. The body typically reacts with increased heart rate, dilated pupils, stimulated sweat glands, and increased alertness. Clearly, these responses are in line with those experienced by people falling in love.

Romantic love, which is the stage after attraction, is associated with an increase in three primary neurotransmitters: serotonin, dopamine, and norepinephrine. Serotonin strongly influences infatuation; people in love have similar levels of serotonin to people with obsessive compulsive disorder, hence why lovers have trouble thinking about anything or anyone else. Not surprisingly, certain anti-depressants, which inhibit serotonin, have been found to block a person's ability to fall in love.

When you are falling in love, your brain also releases more dopamine, which is associated with the integration of thought and emotion, decision making, and stimulates the hypothalamus (which releases sex hormones). Dopamine is triggered by novelty, risk, excitement, and danger. Dopamine and norepinephrine combined, produces a feeling of euphoria and "addiction" to the other person. The problem with dopamine is that our receptors become tolerant to it over time, meaning that the same amount does not produce the same feelings. This is one of the principal reasons why some people struggle to stay in love after the honeymoon period.

We can increase our response to dopamine by engaging in plenty of new and exciting behaviors with our partner, such as going on vacation, engaging in novel activities, having sex in new positions and locations, joining new hobbies together, and making date night a fun and different experience every week. 

The Neurochemistry of Attachment

Once the initial stages of falling in love are over, we begin to feel comfortable in the presence of our partner and our relationship becomes stable in the long term. This is when different brain chemicals start to take over; namely, oxytocin and vasopressin.

Oxytocin, or the "cuddle chemical", is a hormone that is released after sex and is involved in feelings of closeness and intimacy. It stands to reason that a greater level of sex is associated with greater levels of oxytocin. Oxytocin is also released through touch, including kissing, stroking, and hugging. It is also released through talking; hence, we can see why communication is so central to maintaining a good relationship.

Estrogen, which is present to a much greater extent in women, increases sensitivity to oxytocin. This is why women are more likely to fall in love after sex.

When oxytocin was blocked in prairie voles (these are known to mate for life) in a laboratory experiment, they no longer showed devotion to each other and literally moved on. Thus, oxytocin is absolutely fundamental to sustaining lifelong romantic attachments.

Vasopressin is known as the "monogamy hormone," which prompts couples to be faithful to one another. Studies have demonstrated that inhibiting vasopressin causes couples to become less devoted to one another.

Love is a biologically influenced emotion. It is composed of a concoction of a number of different chemicals, which differ depending on which phase of the relationship one is currently experiencing. The early stages are directed by feel-good chemicals (serotonin and dopamine), the fight or flight response, and risk-taking and excitement. The later stages of a relationship are characterized by intimacy, monogamy, and bonding, which are influenced by the release of oxytocin and vasopressin.

The concept of love is not a mystery after all and we know how to sustain long-lasting deeply loving relationships!

To learn more about the science of love and creating happy, lasting relationships in your life, reach out to Marni Feuerman, LCSW, LMFT at or check out her website

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