Why Do We Fall In Love? (The Science Of Love)

Have you ever wondered why do we fall in love? Like any other human emotion, love has both a biological and physiological component. The processes occurring in our brain at the onset of love are governed by the following systems: Sex drive, romantic love, attachment and the reward system.

Let me remind you our scientific evaluation of love doesn’t in any way undermine its grandeur and reduce an ardent emotion so effulgent to another cold mechanical routine. Rather, the article provides scientifically verified information about how to sustain a long-term healthy attachment after the expiration of the ephemeral honeymoon phase, something that is often ignored in these digital, fast-moving times.

Symptoms of Love

This is what poets live for, unless your name is Gwyneth and it doesn’t rhyme with anything. A person in love acquires a heightened sense of attention, focusing it on their partner when in their presence. One also witnesses a wide spectrum of moods, from intense ecstasy when things go well to horrible despair when things are going poorly. Another major addition is an irrational sexual possessiveness or obsession regarding their partner.

However, the dynamics cannot be generalized to a single part and are the result of multiple systems working in synchronization that evolved from continual mating and reproduction.

The Brain’s Role in Love

Relevant Systems

Like any other human emotion, love has both a biological and physiological component. Processes occurring in our brain at the onset of love can be generalized by these systems:

  1. Sex drive: This system deals with what W.H. Auden called “an intolerable neural itch”, our constant craving for sexual gratification.
  2. Romantic love: This system rules the elation of emotions, such as our obsessions and excitement during the early onset of newfound love.
  3. Attachment: The sense of trust and reliability one has for a long-term partner.
  4. The reward system: And finally, the reward system, which is responsible for the ecstatic feeling that love produces. This system resides way below the rational core of our brain. It is a primitive region associated with the cycle of motivation, earning rewards and craving. This is the part of brain that is activated when you reach for a piece of chocolate. 

These systems are a part of complex circuits that are embedded in our brains.

How do these system work?

These systems are propelled by a bunch of chemicals and the vagus nerve. The most important and central being dopamine. This neurotransmitter is a natural stimulant secreted and sprinkled over the regions of our brain as a reward for satisfying a need. Its activity is apparent in the reward system.

Other major players are oxytocin, vasopressin and serotonin, which are released when we cuddle or indulge in romantic conversations. Their roots can be traced to the attachment system, where the release of the former two produce the “calming and trusting” effect generally observed in a mother and her infant’s brain throughout early infancy while being fed and cared for, while the latter is responsible for a deep-seated sense of happiness and satisfaction.

Although technically correct, you don’t want to be this guy.

The vagus nerve connects the brain to the heart and subtly stimulates tiny facial muscles that enable us to make eye contact and synchronize facial expressions with our partner. Also, it adjusts the muscles in your ear to concentrate and track your partner’s voice against background noise.

These chemicals are produced and mixed in heavy quantities during sex, like shades of ink in water. They are especially apparent during an orgasm and are the reason for the intense toe-curling pleasure one derives from it. The whole scheme seems to have a Darwinian purpose to it – getting two people to reproduce and be rewarded in return for rearing infants and sustaining the continuation of our species.

Why “the one” is potentially everyone out there

The problem that neuroscientists and anthropologists love to tackle is why we tend to fall in love with a particular person. Monogamy is not an attribute of just humans, but is also seen in some animal species. Animals such as wolves and swans tend to have ‘favorites’ to mate with, a phenomenon called animal favoritism.

Swans love in lake

Photo Credit : Pixabay

However, monogamy and the notion of true love has been frowned upon lately, due to the realization that love is primarily an organic or biological process. There are multiple factors that determine why we fall for a particular person, including their proximity and what is called a love map – a list of desirable traits one builds unconsciously throughout childhood and adult life.

What we learn from this is that the myth of true love or eternal passion is biologically impossible.

One jumps from person to person, and should, if you feel unhappy with one of them. In its working, love is like a drug, and one of the most addictive, for that matter. And as is true for any other drug, the brain responds initially by providing a periodic shower of dopamine until it builds a tolerance, causing its utility to decrease with the same dose, so higher doses are needed.

This is why the honeymoon phase will diminish and come to an end after some period of time. What a social contract such as marriage or any long-lasting relationship demands is the constant labor and work that comes after it. In modern times, where finding the ideal mate or rejecting one is just a click away, communication has lost its charm along the way. With deliberate efforts and welcoming compromises, one can reach out to anyone rather than inhabiting isolation and counting on the prospect of finding the perfect match. After all, it is not something that happens to us, but something we make together.


  1. Why We Love: The Nature and Chemistry of Romantic Love by Helen Fisher
  2. Ted.com
  3. Love 2.0: How Our Supreme Emotion Affects Everything We Feel, Think, Do and Become by Barbara Fredrickson
  4. Harvard Medical School
  5. National Center for Biotechnology Information


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About the Author:

Akash Peshin is an Electronic Engineer from the University of Mumbai, India and a science writer at ScienceABC. Enamored with science ever since discovering a picture book about Saturn at the age of 7, he believes that what fundamentally fuels this passion is his curiosity and appetite for wonder.

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