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
Does anyone know her contact information (preferably email)? I am doing a research paper on the science behind the feelings of love and I would love to interview her. Great article!
Hello! im currently writing a scientific research paper for my school too. May i see your research paper?
Hi! I am also writing a research paper, would you mind sharing any of your sources with me? Maybe we can proof read each others work?
Hello my fellow intellectuals! I am currently indulging in some adverse learning for an anatomy class as well. Would you be so kind as to share some sources to see if mine are credible enough? Oh and before I forget can I see how you guys formatted your paper to check if I’m doing it right?
Can you share your paper work I’m interested in reading
Thanks for all of the information! This will be a great help to our undergrad biopsych project!
Loved your article………
Hormones are synthesized in small amounts but leaves a great impact on individuals and society ………. seriously!!???
I and my lover had been apart for 7 months until my sister told me about a spell caster who had helped her, She said the man was very powerful and that he could help me too. The name of this powerful man is Robinson buckler, after I contacted Robinson buckler in the next 48 hours my ex lover came back to me on his knees begging for my forgiveness and for me to accept him back. It was unbelievable as I was very surprised and happy I finally have him back after several attempts trying to get him back. Robinsonbuckler@ hotmail. com is too strong and contains no negative effect because it’s just like the love spell opened his eyes for him to see how much I truly love him.
do you really want someone who has to be under a “spell” to be with you?
frankly, if you love him, you’ll let him be free, not try to keep him in a cage, however immaterial that cage may be
Really.
will this work even if he has started to move on.
Worthless . . . he didn’t choose you freely . . . it’s not love. It’s control and manipulation and captivity.
Brilliant. Spent the day in a semi meltdown which led me to wonder if this was indeed the culprit. Explains it beautifully. Thank you.
I don’t believe this is all just chemicals. If that’s the case it would be a valid defense in court to just blame chemistry for everything.
To be honest, humans probably do not even have free will. Our bodies have to obey the physical laws of the universe, but in order to predict what someone will do we have to know the starting conditions of almost everything. Because this truth alludes us, we explain it by saying we have free will, just like we explain miracles as phenomena. In reality, and court cases, while the chemical imballance standpoint could be argued, that would either be too out there to be valid, or it would be the same as arguing they were not mentally aware of their actions.
Some truth to the free will argument… I believe without the creators spirit involved we will live lives mostly chemically… the goal then becomes, how can I capture the creator’s spirit and live the life I was created to live to a greater potential… an iPhone never charged just looks like a functioning iPhone till you get up close.,.
I honestly think you are right. I recently was diagnosed with graves disease is an autoimmune problem. According to my Endocrinologist specialist he referred my hormones to be off the charts. I have little to no control over the my state of mind. These hormones sometimes can be so evil. They have attacked my body and mind. To the point I have reverted back to my past traumatic events. Including past broken relationships. I am so broken up by it. I can actually feel like my soul is being ripped off of me. Or at least that’s how it feels. I am depressed. I cannot decipher with my medication treatment if I am coming or going. Is perhaps the worst feeling I have ever experienced. My only hope is to go to the one who has designed me and ask for help. From my mind and heart this disease has distorted my rational thoughts. I hate this feeling. And I hope to God he sees me through it
I am so sorry to hear this happened to you. My father had thyrotoxicosis, side effects of Cordarone arrhythmia medication. It was horrors, at some point his paranoia got a friend hallucination and that was pure torture. Very seldom he’d have moments of clarity and we could joke about it. But mostly it was dark. Hormones try to control us, that’s what I used to say to my son when he hit puberty. Every day I would remind him that while we can’t control the hormones released by out bodies, we can teach ourselves to be aware of what is happening and establish control over things that needs to be controlled and let other things fly free. It might not apply to you 100%, but still it could help, definitely helped my father to some extent. Our body is magical, whoever created is was a mad genius, it’s like a circle: sometime you smile because your brain released dopamine, and sometimes you force a smile and after a while your brain releases dopamine.
Finally someone with a similar view to mine! But thinking that way in daily life isn’t great, from personal experience it can become an excuse for not doing good things- basically we don’t really have a free will in most things but thinking that way makes us do “bad” stuff easier.
Sorry if I’m rambling, it’s late (early more like) and I love this topic.
But yeah apart from hormones love seems to be kind of a social construct, like the biology + society create the amazing thing we have (not saying you can’t be happy without it, plenty of aro/ace or just single people are happy)
Additionally, people going to the gym will in love with each other 😅😂😂
Is that possible 🙄
If you think love is just some sort of thought, it could be argued that it is still controlled by the brain. As is religious belief (controlled by a specific part of the brain nicknamed the ‘religious’ brain) and other emotions. So essentially, everything you believe in, feel, hate, is all controlled by the brain. However, I’m not stating that god is real or fake or that all religions believing in a god or more is fake, I’m just simply stating it’s all functions of the brain to believe in god or gods or to feel love.
Truly, a bunch of nonsense. Man is so in love with sin that he/she will debase himself to any low level just to avoid coming into the Light of God. Man’s refusal to accept his moral responsibility. Man (and women) who are in love with sin and go to any extreme to try and convince others that their sin is okay. Wow. These last few years demonstrate the truth of all the words of the bible. Man’s judgment by od for sin is surely just.
Truly, a bunch of nonsense
What the heck WAS that???
Adam, you are right!
We were all given a free will at Creation when God made us in His image. That is what differentiates us from animals. (That is also why animals do not go to court lol.)
I can truly agree with your statement. I often wonder if we were created In a God likeness and image. And he loved us first. That’s how we know love. That perhaps that was his purpose. That we would seek him . Because his the only one that can truly fulfill that void and reveal the true meaning of his divine grace.
Apparently we need to write the name of who we are responding to on here or our responses likely make no sense and likewise the pronouns such as it and they do need a proper antecedent clearly defined as they are not otherwise evident here as well on these responses. Yes, great article. Thank you. And to Lydia – god is a construct made up by man. I sincerely doubt man is a construct made up by god. And for a number of other respondents – if you do read much about science, you will find that our bodies are very far from perfect. Rather, our physiological and anatomical construction is truly rather a mess.
Are we really that different from animals though? Like in what way do we have more free will than animals?
(By the way, I’m not attacking your religion, just debating on the particular free will + animals argument, religion is great as long as it doesn’t harm anyone)
The more you delve into psychology, the more you see how everything affects our thoughts and our actions.
On the flipside, how can you say animals don’t have free will if there’s literally lions adopting gazelle/antelope (forgot which one specifically I always get them mixed up) kids, raising them as their own and never eating them?
Hate to make everything political, BUT — both the infatuation /love discussion and dislike for those different from ourselves in this great article make me think seriously that it might explain some big problems we currently have in the White House. Has this been shared with appropriate circles in Washington? I pose this with all seriousness.
You seriously need to beat it!
>Hate to make everything political
>Makes everything political
Go write a blog or something
Since love Is caused by the chemicals dopamine, serotonin, norepinephrine and oxytocin you could say every time you fall in love it could be the beginning of a Chemical romance I’m sorry I couldn’t help it
😂😂😂😂 that’s actually a pretty good one!
;-D. Good response. I needed a bit of humor. Thank you for posting.
No apology needed- when 2 people fall in love that is even referred to as ‘they have great chemistry’…
LMAO i gasped so loud seeing that
Very scientific and interesting analysis… excellent!!!!
Is there drugs out there, that can block these chemicals so that we can never be attracted & attached to a significant other, therefore we can never be hurt by love and stay content and happy as a single free human?
A positive interaction between two (or more) humans with verbal and non-verbal cues triggers an orchestra comprising of chemical neurotransmitters and electrical synaptic discharges which results in a symphony which is unlikely to be replicated by the action of a soloist in the form of a single pill. Multiple psychotropic pills given in an attempt to produce similar effects often result in cacophonies leaving the mind in a state which is sometimes worse than the problem it tried to rectify. This may be due to drug interactions, side effects or withdrawal symptoms. This is not to say that medications for the mind are useless or harmful but that the human element is irreplaceable even when medications of proven value are administered.
I can speak from personal experience about what George is saying. I was taking an ADD medication called Dexedrine. One of the effects of Dexedrine is that it boosts dopamine levels. It had lots of very harmful side-effects. Coincidentally this was around the same time that I was falling in love with someone, and I can tell you the experience was at least 10 times worse for everyone because of the medication.
Agreed! Thank you for sharing. Needed to read this tonight.
Read ‘two cures for love’ by Wendy Cope. No medication required.
It wouldn’t be blocking the chemicals, it would be blocking the receptors of this chemicals. You block these receptors by providing them with chemicals outside the body’s self production. Drugs that can do that are antidepressants, and others like amphetamines. Of course there are always side effects, and withdrawal symptoms. So there is no way to continously block these receptors and be 100%, 24/7 happy.
hi..i also want to know about this..did u get answer?plz letvme know if there are medicines
Anti psycothic blocks the uptake of dopamin. Main component in lust and attraction.
It is a decision we Make. When I am tempted, I quickly go to what I have at home. I make myself feel what I would loose if I chose this immediate gratification that is stupid layer but pleasurable now. I think about how I would hurt my husband and children and family and friends. Then I think, is it worth it? We have free will. We must teach our children this and understand that we want to have free will and not be a robot. Then and only then is when we can be darn proud that we made the best decision.
This was for B. Oct 11, 2019
We were designed for relationships. That is a fact and the science only confirms the design. Any attempt to lean into self for total fulfillment will only short circuit the creation. Don’t be fooled by hurt… it is a mechanism of our creation to seek safety at times, but when mastered and processed in the presence of the designer, the opportunity for deeper love, more fulfillment, tighter bonds, etc etc… will occur… you can see a similar process in sports, careful diet, sabbath rest (originated by the creator him/her self), and many other areas… learning to embrace hurt and learn that feelings are not bad, it’s what we do with them that can be bad…
Thats gold. Thanks for sharing this.
Hi Thomas,
I read your excellent question and some of the replies. I wanted to say that I have clinical depression and take medicine to manage it. It doesn’t keep me from falling in love and it doesn’t keep me from feeling pain when I am rejected or betrayed. I too have longed to simply be content by myself and never have to deal with the highs and lows of love again. Sometimes I even get a little mad at God for letting me fall in love when I was content and had no desire for a relationship, then the love is totally one sided and I get crushed again. What I have learned is that there is no quick fix and it is not God’s fault that human emotions are so topsey-turvey. It’s the fault of sin in the world; the same thing that screwed up everything else. The only remedy for that is a relationship with Jesus Christ. He died to pay for our sins and he rose from the dead to defeat death. If we tell Him how screwed up we are and that we don’t want to be that way and tell Him that we accept, and believe God accepts, His payment for our sins and ask Him to come into our lives and be the master of them He will. He will transform our lives and and give us what we need for every day living and when we die, take us to heaven. Will we still fall in love sometimes? Probably. Will that relationship possibly not work out and end with us being very hurt and going through great pain for a while? Possibly. But it will not be as bad with Him as it was without Him. And He is the only one that can really do anything about it inside us where it hurts. I know he loves you Thomas, because I know he loves me and I am not a very lovely person. Please think this over and be encouraged.
Amen!Amen! I think you are a Lovely person Anna , just for speaking this truth. 🙌🏼🥰
God bless you. I agreed and I believe in your philosophy.
Well said. I will take your advice in the matter .
Well said. The real need is hidden but it is hunger for God.
i aint readin allat 🙏💯
Self dependent is the way to be happy alone
preach brother.
I feel exactly the same way! I think I am in love with this older dude at work (or at least have very strong feelings) and it’s a ‘bit’ of a struggle always trying to hide and supress these feelings. I am terrified of rejection, doing something idiotic or being taken advantage of, but like this researcher said sometimes these chemicals cloud your judgement causing you to do crazy shit! I just wish I could stop feeling this way, (so intensely! ) and go back to my normal, boring, stress free life. zero romance = zero hassle!
But then I get to wondering is it worth it? with the right person in a mutual relationship? I imagine there could be no better feeling!
Completely right way to think.
Fair well.
These surges which person feels in love r not only associated with the euphoric love like conditions but these neurotransmitters also involves in the normal physiological homeostatic functions of body…so if drug for the inhibition of release of these neurotransmitters(chemical) will b taken it will disturbe their normal basal homeostatic levels……
yes there’s drugs out there you just see them
Hopefully we can all manage to at least have that much control over ourselves ….
I’ve known young guys who were so horny they had to step into a restroom or someplace 3 times a day and yet they were able to stay married and faithful. But perhaps they were simply more mature than whoever it is you’re referring to.
@Katherine Wu…Wow, what a nice article. What you say of the ‘liberation’ (freedom to think and act as self) as the fourth component in love with/without lust, attraction, and attachment? I don’t have a reference than me itself for now.
Yes, interesting point!
Oxytocin…having a dog, does one’s hormone increase. Heard dogs are good
For people who are depressed.
yes friendship with an animal can have many of the same benefits as human friendships including oxytocin and bonding. please educate yourself to a dogs social and other needs before adopting because the pet has no choice in the matter so you have a higher duty to treat a pet apropriately and give it a decent life. please consider volunteering at a rescue or shelter before committing to adopting, you will learn so much and help so many animals and people and that helps depression too.
Fostering is fantastic too. Since you are helping them out and have the option to adopt but if you know your living or work situation may cause you to move often its not going to ruin things for everyone.
I beleive masturbation place a big role in releasing oxytocin. So I would recommend it for everyone.
You are partially correct my friend! Masturbation increases your bond to yourself and considers all other relationships threatening to that bond… so you can see the dilemma involved! What’s more, if we sidestep it a bit and fall for this, dopamine kicks in at way too high a level too. If our other relationships or activities can’t keep supplying this ‘new normal’ (becomes IMPOSSIBLE actually) for dopamine, we further push others away to try to enjoy the “mother lode” of dopamine that is never enough… so much more but that’s enough for now…
Me too!! With a light touch of MY own erotica fantasy.
I enjoy it the most when it’s just me, my world, taking care of me, myself without any subjective feelings of having to please my mate, performative.
Each one has qualities that I enjoy, so for me it’s like ice-cream, I love several kinds, but My favorite and always go to is Strawberry!
Amen brother, amen
No please I think it’s not safe because masturbation makes love between man and woman useless,you will one will think that that normal way is now of no importance so please atlest I reject masturbation
It never felt good to me; it had an addictive quality, like binge eating. It took a while, but finally, I gave it up, and feel better since.
Like quitting chocolate, or alcohol, I found the urge waned. I feel more balanced without its “driving” presence.
how dare you lecture him! i grew up with dogs and most families have one. Volunteer at a dog shelter is so good over the top,
Krishna is the answer to every question that arises in your mind.
your comment sounds like religious faith trumping scientific enquiry
Hari bol 😍🙌
Read Bhagavad Gita, it is one solution to many problems.
I don’t think this is true. Findings on pets and depression are mixed with many saying that owning a pet doesn’t ward away depression.
I think it has to do with the eye contact a dog makes with humans.
obviously the science to love is money
no its not
its important in 21 century. but it is not predicator for the people that have enough money to live a decent life
If they make a good sandwich after sex, that’s love.
Yes the sandwich test. Any unexpected sandwich is proof of love. Dont ever let a woman who feeds you get away… specially if she haa a killer body.
If that sandwich is for other guy, not for you, then…
If either of you can make a sandwich after sex, you’re doing it wrong.
Agree totally to this… love is to give
Is this reading between the lines sort of.
I recommend you making your own sandwich before allowing your pile of money seduce you into rubbing one out… Wash up before enjoying your amazing sandwich and restacking your bills (with a big grin on yo face)…. 😉
😂
You just love money
I breathe air 🙂
Notes for the author:
Good but there is a missing term in the second sub-section of the attraction section.
No one asked…..
[responding to kjkjlkjlkjl]
No I know what they mean, it says, “including the ______ and the caudate nucleus”, where I’m sure the author meant to insert the name of a region but forgot, or it didn’t quite make it to the final copy.
Oxytocin and serotonin are Released when petting a cat, dog, and when you achieve success health, and wealth. There are feelings of euphoria and oxytocin too. 🐕 Dogs and cats 🐱 don’t judge people like other groups of people do. Joseph.
Yes , Love is about attachment, love is about beauty, love is about life, love is life and the most beautiful and powerful thing you can give and get!! TTT
Beautiful article btw, thank you for sharing!! TTT
that sounds good
bro u good?,,,,,,,,,,,,
Pet dogs give unconditional love. They help us feel safe and surrender themselves to our care thus giving us the good feelings we get on parenting.
Lovely article.
MJ, As I understand it, because dogs give off about 35% Oxytocin, that causes our mirroring neurons to reflect that and produce more! The last I read, cats only have about 19% release of the same! Does that make sense?