by Katherine Wu
figures by Tito Adhikary
In 1993, Haddaway asked the world, “What is Love?” I’m not sure if he ever got his answer – but today, you can have yours.
Sort of.
Scientists in fields ranging from anthropology to neuroscience have been asking this same question (albeit less eloquently) for decades. It turns out the science behind love is both simpler and more complex than we might think.
Google the phrase “biology of love” and you’ll get answers that run the gamut of accuracy. Needless to say, the scientific basis of love is often sensationalized, and as with most science, we don’t know enough to draw firm conclusions about every piece of the puzzle. What we do know, however, is that much of love can be explained by chemistry. So, if there’s really a “formula” for love, what is it, and what does it mean?
Total Eclipse of the Brain
Think of the last time you ran into someone you find attractive. You may have stammered, your palms may have sweated; you may have said something incredibly asinine and tripped spectacularly while trying to saunter away (or is that just me?). And chances are, your heart was thudding in your chest. It’s no surprise that, for centuries, people thought love (and most other emotions, for that matter) arose from the heart. As it turns out, love is all about the brain – which, in turn, makes the rest of your body go haywire.
According to a team of scientists led by Dr. Helen Fisher at Rutgers, romantic love can be broken down into three categories: lust, attraction, and attachment. Each category is characterized by its own set of hormones stemming from the brain (Table 1).
Let’s Get Chemical
Lust is driven by the desire for sexual gratification. The evolutionary basis for this stems from our need to reproduce, a need shared among all living things. Through reproduction, organisms pass on their genes, and thus contribute to the perpetuation of their species.
The hypothalamus of the brain plays a big role in this, stimulating the production of the sex hormones testosterone and estrogen from the testes and ovaries (Figure 1). While these chemicals are often stereotyped as being “male” and “female,” respectively, both play a role in men and women. As it turns out, testosterone increases libido in just about everyone. The effects are less pronounced with estrogen, but some women report being more sexually motivated around the time they ovulate, when estrogen levels are highest.
Love is its Own Reward
Meanwhile, attraction seems to be a distinct, though closely related, phenomenon. While we can certainly lust for someone we are attracted to, and vice versa, one can happen without the other. Attraction involves the brain pathways that control “reward” behavior (Figure 1), which partly explains why the first few weeks or months of a relationship can be so exhilarating and even all-consuming.
Dopamine, produced by the hypothalamus, is a particularly well-publicized player in the brain’s reward pathway – it’s released when we do things that feel good to us. In this case, these things include spending time with loved ones and having sex. High levels of dopamine and a related hormone, norepinephrine, are released during attraction. These chemicals make us giddy, energetic, and euphoric, even leading to decreased appetite and insomnia – which means you actually can be so “in love” that you can’t eat and can’t sleep. In fact, norepinephrine, also known as noradrenalin, may sound familiar because it plays a large role in the fight or flight response, which kicks into high gear when we’re stressed and keeps us alert. Brain scans of people in love have actually shown that the primary “reward” centers of the brain, including the ventral tegmental area and the caudate nucleus, fire like crazy when people are shown a photo of someone they are intensely attracted to, compared to when they are shown someone they feel neutral towards (like an old high school acquaintance).
Finally, attraction seems to lead to a reduction in serotonin, a hormone that’s known to be involved in appetite and mood. Interestingly, people who suffer from obsessive-compulsive disorder also have low levels of serotonin, leading scientists to speculate that this is what underlies the overpowering infatuation that characterizes the beginning stages of love.
The Friend Zone
Last but not least, attachment is the predominant factor in long-term relationships. While lust and attraction are pretty much exclusive to romantic entanglements, attachment mediates friendships, parent-infant bonding, social cordiality, and many other intimacies as well. The two primary hormones here appear to be oxytocin and vasopressin (Figure 1).
Oxytocin is often nicknamed “cuddle hormone” for this reason. Like dopamine, oxytocin is produced by the hypothalamus and released in large quantities during sex, breastfeeding, and childbirth. This may seem like a very strange assortment of activities – not all of which are necessarily enjoyable – but the common factor here is that all of these events are precursors to bonding. It also makes it pretty clear why having separate areas for attachment, lust, and attraction is important: we are attached to our immediate family, but those other emotions have no business there (and let’s just say people who have muddled this up don’t have the best track record).
Love Hurts
This all paints quite the rosy picture of love: hormones are released, making us feel good, rewarded, and close to our romantic partners. But that can’t be the whole story: love is often accompanied by jealousy, erratic behavior, and irrationality, along with a host of other less-than-positive emotions and moods. It seems that our friendly cohort of hormones is also responsible for the downsides of love.
Dopamine, for instance, is the hormone responsible for the vast majority of the brain’s reward pathway – and that means controlling both the good and the bad. We experience surges of dopamine for our virtues and our vices. In fact, the dopamine pathway is particularly well studied when it comes to addiction. The same regions that light up when we’re feeling attraction light up when drug addicts take cocaine and when we binge eat sweets. For example, cocaine maintains dopamine signaling for much longer than usual, leading to a temporary “high.” In a way, attraction is much like an addiction to another human being. Similarly, the same brain regions light up when we become addicted to material goods as when we become emotionally dependent on our partners (Figure 2). And addicts going into withdrawal are not unlike love-struck people craving the company of someone they cannot see.
The story is somewhat similar for oxytocin: too much of a good thing can be bad. Recent studies on party drugs such as MDMA and GHB shows that oxytocin may be the hormone behind the feel-good, sociable effects these chemicals produce. These positive feelings are taken to an extreme in this case, causing the user to dissociate from his or her environment and act wildly and recklessly. Furthermore, oxytocin’s role as a “bonding” hormone appears to help reinforce the positive feelings we already feel towards the people we love. That is, as we become more attached to our families, friends, and significant others, oxytocin is working in the background, reminding us why we like these people and increasing our affection for them. While this may be a good things for monogamy, such associations are not always positive. For example, oxytocin has also been suggested to play a role in ethnocentrism, increasing our love for people in our already-established cultural groups and making those unlike us seem more foreign (Figure 2). Thus, like dopamine, oxytocin can be a bit of a double-edged sword.
And finally, what would love be without embarrassment? Sexual arousal (but not necessarily attachment) appears to turn off regions in our brain that regulate critical thinking, self-awareness, and rational behavior, including parts of the prefrontal cortex (Figure 2). In short, love makes us dumb. Have you ever done something when you were in love that you later regretted? Maybe not. I’d ask a certain star-crossed Shakespearean couple, but it’s a little late for them.
So, in short, there is sort of a “formula” for love. However, it’s a work in progress, and there are many questions left unanswered. And, as we’ve realized by now, it’s not just the hormone side of the equation that’s complicated. Love can be both the best and worst thing for you – it can be the thing that gets us up in the morning, or what makes us never want to wake up again. I’m not sure I could define “love” for you if I kept you here for another ten thousand pages.
In the end, everyone is capable of defining love for themselves. And, for better or for worse, if it’s all hormones, maybe each of us can have “chemistry” with just about anyone. But whether or not it goes further is still up to the rest of you.
Happy Valentine’s Day!
Katherine Wu is a third-year graduate student at Harvard University. She loves science with all of her brain.
Further Reading
- For a long-form human interest story on love, see National Geographic’s coverage of “True Love”
- For a very in-depth (and well-done!) introduction to the brain and its many, many chemicals, check out the NIH’s Brain Basics page
- For the New York Times’ take on falling in love with anyone, ask these 36 questions
FAQs
What is the science behind love and lust? ›
The initial happy feelings of being in love is stimulated by 3 chemicals in the brain: noradrenaline that stimulates adrenaline production causing that racing heart and sweaty palms; dopamine, the feel-good chemical; and phenylethylamine that is released when we're near our crush, giving us butterflies in our tummies.
What three chemicals does the author mention in her study about love? ›Refer to one or more details in paragraph 3 of the text to explain why the author chose to look specifically at these three chemicals in the brain--dopamine, norepinephrine, and serotonin--in her study of romantic love.
Is there any science behind love? ›But did you know that the science behind love is just as complex? It's one that involves not only chemical reactions in the brain, but also all five senses and their related organs. “When people fall in love, there's a lot happening at the neurochemical level,” says Dr.
What brain chemicals are released when falling in love? ›The brain seals the deal by releasing oxytocin, often called “the love hormone.” It's a neuropeptide produced in the hypothalamus and secreted by the pituitary gland during times of intimacy, like hugging, breastfeeding and orgasm.
Can you confuse lust for love? ›So, it depends who you ask. He defines lust as a state of overwhelming sexual and physical attraction to another person. “Love, on the other hand, is a much broader concept that includes deeper emotional connection and, usually, a desire to make that relationship last,” he says.
Can love grow from lust? ›Relationship experts agree lust can turn into love — but warn that feeling lust does not guarantee an eventual loving relationship. "Sometimes lust can lead to love and is often experienced within a loving relationship.
What causes people to fall in love? ›According to Hani Henry, chair and associate professor of psychology in the Department of Sociology, Anthropology, Psychology and Egyptology at AUC, Robert Sternberg's psychological theory covers the most common reasons why we fall in love, namely: intimacy, passion and commitment.
What makes men fall in love? ›Physical attraction, sexual compatibility, empathy, and emotional connection are key to making a man fall in love with a woman.
What chemical is in the brain for love? ›Oxytocin, known also as the love hormone, provokes feelings of contentment, calmness, and security, which are often associated with mate bonding.
Does falling in love happen naturally? ›Falling in love is usually the autonomous process that happens quite naturally when you meet a person who clicks you. This phase is often referred to as the attraction phase or the honeymoon period. This is the most exciting stage of falling in love. But with time, the excitement dissipates gradually.
What is an intense attraction to someone? ›
Lust. This describes intense feelings of passion, desire, affection, or attraction toward someone.
How long does love last scientifically? ›How long does the romantic phase last? Studies have estimated the euphoric stage can last anywhere from six months to two years.
Does orgasm release oxytocin? ›Most of the studies found higher levels of oxytocin during the orgasm or ejaculation. Given the sexual arousal evoked by self-stimulation in which sexual fantasies play an important role, it should be possible to postulate for a role of the oxytocin in sexual desire.
What releases oxytocin in a woman? ›Your hypothalamus makes oxytocin, but your posterior pituitary gland stores and releases it into your bloodstream. Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, muscles and other tissues.
What causes a man to bond with a woman? ›Emotional vulnerability
Research shows that by being emotionally vulnerable with each other, couples can bond with each other. It can deepen the love between them in a significant way. Emotional vulnerability can be the key to what makes a man fall deeply in love with a woman.
Your palms may perspire. You experience butterflies around someone. You want to touch the person frequently. You want to leave after having sex with somebody instead of staying to spend time with them.
How long can a man lust after a woman? ›It can last up to two years. Lust is often the first phase of 'love,' but lust doesn't always develop into a loving romantic relationship. However, when you are in a relationship and don't realize the difference between love and lust, it can be difficult to tell whether the relationship has the potential to last.
Is love more powerful than lust? ›Lust is not stronger than love. It's a temporary sexual desire that may lead to love. Love is a powerful force that pulls two individuals into a relationship.
What emotion is deeper than love? ›Being enamored of something or with someone goes far beyond liking them, and it's even more flowery than love. Enamored means smitten with, or totally infatuated. Someone enamored with another will perhaps even swoon.
What emotion causes lust? ›Lust is driven by the desire for sexual gratification. The evolutionary basis for this stems from our need to reproduce, a need shared among all living things. Through reproduction, organisms pass on their genes, and thus contribute to the perpetuation of their species.
What are the three stages of love lust? ›
The three stages include lust, attraction and attachment.
Do we choose who we fall in love with? ›Yes, sometimes we can choose whom we love. At the same time, powerful emotions drive the way we feel. It can be tough to decide where the feelings end and where our rationality takes over. In stressful times, you can make the choice to keep on loving someone rather than leaving them.
Can you control who you fall in love with? ›More important, you can choose not to fall in love with someone. To be precise, you can choose to avoid situations where you might fall for somebody you shouldn't. Just as important—but more difficult in practice—you can choose to try to stop being in love with someone who turns out to be wrong for you.
How to make him subconsciously want you? ›- 01/8Keep these tips in mind. ...
- 02/8Texting time. ...
- 03/8Let him talk about himself. ...
- 04/8Laugh at all his jokes. ...
- 05/8Touch his shoulder. ...
- 06/8Show the care. ...
- 07/8The gaze. ...
- 08/8The body language.
Signs of an obsessive lover
* Feeling of “ownership” over another person. Feeling extremely jealous if they interact with other people. * Having extremely strong feelings towards the other person even without having spent much time with them.
Heterosexual men tend to be attracted to women who have a youthful appearance and exhibit features such as a symmetrical face, full breasts, full lips, and a low waist–hip ratio.
How do you tell if a man loves you? ›- 8 types of love:
- He embraces all parts of you.
- He talks about a future with you.
- He's supportive.
- He makes an effort to grow closer.
- He's vulnerable with you.
- He prioritizes you.
- He meets you halfway.
Researchers have scanned the brains of people who are madly in love and found a heavy surge of dopamine, a neurotransmitter in the brain's reward system that helps people feel pleasure. Dopamine, along with other chemicals, gives us that energy, focus, and obsession we feel when we're wild about someone.
What part of the brain controls love and hate? ›The hypothalamus acts as a regulator of emotion, controlling levels of sexual desire, pleasure, aggression and anger.
What happens to you when you fall in love emotionally? ›Researchers concluded that falling in love is much like the sensation of feeling addicted to drugs with the release of euphoria, including brain chemicals like dopamine, oxytocin, adrenaline, and vasopressin.
What is the 3 month rule? ›
The three-month rule prescribes that people should put potential partners through a trial period, during which the partner is evaluated on how good of a fit they are. A TikToker with the username Manifestingbabe spelled out the three-month rule.
Do older guys fall in love faster? ›Many men actually fall in love pretty fast On average, it can take a man a few months (around 88 days,) before he's in love. Of course, it depends on the man. Often a younger man falls in love faster, while an older man may take a while.
How many times do we fall in love? ›A study has shown that a person can fall in love at least three times in their lifetime. However, each one of these relationships can happen in a different light from the one before and each one serves as a different purpose.
What makes you instantly attracted to someone? ›Why we feel instant attraction to some people, and not others, is affected by lots of different things: mood, hormones and neurotransmitters, how alike we are, the shortage of other partners available, looks, physical excitement, and the proximity of geographical closeness.
Can you sense when someone is attracted to you? ›The clues aren't always obvious, but you can see some of them by paying attention. When someone finds you physically attractive, it shows by always making eye contact, always wanting to touch you physically, and frequently initiating conversations.
What makes you most attracted to someone? ›They include physical attractiveness, proximity, similarity, and reciprocity: Physical attractiveness: Research shows that romantic attraction is primarily determined by physical attractiveness. In the early stages of dating, people are more attracted to partners whom they consider to be physically attractive.
Can you love someone forever? ›But is it actually possible for love to last forever? The definition and duration of love can be debatable, but research suggests that love is frequently resilient – and, in some cases, it can last longer than a lifetime.
Can you grow to love someone you are not attracted to? ›For this reason, an individual can definitely be in love with someone without feeling sexually attracted to them. If you choose to stay with your partner, then you need to be aware that such a relationship poses a unique set of pitfalls and problems which both of you need to be aware of, and to address as they arise.
What does true love feel like? ›Passionate love feels like instant attraction with a bit of nervousness. It's the "feeling of butterflies in your stomach,"Lewandowski says. "It's an intense feeling of joy, that can also feel a bit unsure because it feels so strong."
Where do you touch a girl to release oxytocin? ›Its best to begin with light small touches on the arms and hands, to make the oxytocin effect kick in. Take her hand while taking to her (never ask for it, just take it), play thumb wrestling or pretend to read her palm or just play footsies under the table.
Where do you touch a guy to release oxytocin? ›
Men have been shown to be particularly sensitive to physical contact, so touch likely boosted their oxytocin levels considerably, Melton says. “Justifying small ways to make any activity one where we're touching our partner, whether that's touching of the arm or around the shoulder, [could be useful],” Melton says.
Do men cuddle with oxytocin? ›The cuddle hormone
Men also have oxytocin, but it is compensated for by higher levels of testosterone - so they are less prone to cuddling!
Biological differences aside, men and women appear to experience oxytocin in many of the same ways. It facilitates bonding with children, increases romantic attachment, and plays an important role in reproduction for both sexes.
How do you trigger oxytocin? ›Hugging, kissing, cuddling, and sexual intimacy can all trigger oxytocin production, which can strengthen bonds between adults, too. These effects have led oxytocin to be grouped with the other happy hormones — hormones known to have a positive impact on mood and emotions.
What keeps a man to one woman? ›To keep him in love with you, you need to show kindness and consideration to your man to let him know you care about him. Some people believe that they expect their men to know how considerate they are, but this is not true. If you are considerate, you need to show it because he will need it during his trying times.
What do men do when they're falling in love? ›Men Fall In Love When They Can Make Their Partner Happy
If a man makes gestures that make you feel good, whether doing thoughtful things for you, giving you small, unexpected gifts, or paying you sincere compliments, he's likely trying to make you happy.
When a woman notices that a man is more concerned with gratifying himself, ignoring her, or having poor hygiene, she may lose interest in him. Additionally, if a woman does not enjoy sex with a man, it can lead to a lack of interest in the relationship.
How does lust turn into love? ›- Make Sure You Actually Like Him. I cannot stress this enough. ...
- Read the Room (aka. HIM) ...
- Drop Some Hints. Depending on how clueless he is, this can either seal the deal or get you absolutely nowhere. ...
- Shoot Your Shot. Make your move and be assertive! ...
- Be Patient. ...
- Live Your Own Life.
Sudden Engagement vs Deep Commitment: Under love vs lust, the feeling of love typically makes for a long term relationship. If you are deeply in love with someone, you are committed to meeting the needs of such a person. Lust on the other hand is short and sudden and never lasts for a long time, unlike love.
Why do we fall in love with certain people? ›Compatibility, attractions, connection, similar interests, and communication are important reasons that make you fall in love. Some people may feel attracted to their partner's sense of humor, calm demeanor, jovial nature, and emotional intelligence.
What are the 5 stages of love lust? ›
- Lust, or erotic passion.
- Attraction, or romantic passion.
- Attachment, or commitment.
Raw Lust — Testosterone. The Cambridge Dictionary describes lust as a very strong sexual desire. It's about sexual gratification that stems from our innate desire to reproduce — the purest form of physical attraction.
What does intense lust feel like? ›Lust is a high that can feel like an addiction and consume all your mental space; it's closely linked with infatuation. Love holds a more balanced perspective and allows for the ability to maintain a balanced life.
What is bigger than lust? ›“Usually, infatuation type of love is more powerful than just lust because lust is contained within a good, strong infatuation. And that infatuation is one of the most powerful emotions that humans can feel. It's a force to be reckoned with.”
Why is lust the biggest enemy? ›Then again, when lust is unsatisfied, it turns into wrath; wrath is transformed into illusion, and illusion continues the material existence. Therefore, lust is the greatest enemy of the living entity, and it is lust only which induces the pure living entity to remain entangled in the material world.
What triggers love in a man? ›Physical attraction, sexual compatibility, empathy, and emotional connection are key to making a man fall in love with a woman.
Who falls in love faster male or female? ›Contrary to popular belief, women don't fall in love quickly. Actually, science said in relationships between cisgender men and women, men are more likely to declare love at first sight. A new study found men actually fall in love quicker than women, and the reason could be biological.
Why do we always fall in love with someone we can't have? ›Romantic rejection can lead to increased yearning because it stimulates parts of the brain associated with motivation, reward, addiction, and cravings. New research also suggests the reasoning individuals fall for the unavailable may actually be scientific, some people cant help it.