Science, Now + Beyond

This is the science behind falling in love – and it isn’t fate

Your heart starts racing. Your palms start sweating. You feel butterflies in your stomach.

Your heart starts racing. Your palms start sweating. You feel butterflies in your stomach. The sky looks bluer today. You can’t focus on work. Bottom line is, you probably can’t focus on anything that’s not your crush. And these are just some of the common side effects of “falling in love.”

Whether you’ve experienced it for yourself or seen someone behave like a dork or act like they’re on a “pink cloud” (as I like to call it), then it’s most likely that “love” has triggered a bunch of chemicals that are making them behave this way.

Turns out, there’s a science of love.

Let’s start with how it all begins. Is love at first sight even real? Well, according to a science-based study by Arthur Aron, the mind of a person takes between 90 seconds to 4 minutes to determine whether they are struck by love or not. This “choice” is influenced by the following factors: 55% by their body language, 38% by the person’s voice, and 7% by what they’re actually saying.

So are we making a rational choice when we choose who we fall in love with? Probably not. This is how it all works in our bodies and the stages we go through according to a study from Rutgers University.

1. Lust

Couple kissing passionately

This stage is driven by sex hormones (estrogen and testosterone) in our bodies. People choose partners with chemicals that complement their own; for instance, someone with high estrogen might be attracted to someone with high testosterone levels.

This leads on to the next stage:

2. Attraction

This stage right here is exactly what I was talking about at the beginning. It is when we are “crazy in love,” or love-struck.

It can all be traced back to dopamine, a neurotransmitter in our brain and adrenal glands that increases the release of testosterone. It also affects sweat glands, genitals, and the senses. While dopamine makes us feel happier and excited by lifting our mood, testosterone increments our sexual desire and aggressive behavior (which explains why we intensely pursue our crush).

The neurotransmitters norepinephrine and phenylethylamine explain why we can only think about our crush. While norepinephrine (a stimulant) explains why we can’t sleep, have high alertness, and happen to remember small details about our crush, phenylethylamine explains why we lose our appetite and feel giddy.

Throughout this process, a feedback loop or brain reward system begins, which involves the central nervous system, neurotransmitters present in the bloodstream, and various parts of the body (i.e. stomach, skin, genitals). Simply put, once the brain realizes that there’s pleasure when our crush touches our skin, it starts seeking this reward more and more.

Other chemicals like serotonin, adrenaline, and cortisol are also present during this stage of falling in love. Adrenaline and cortisol increase our heart rate and likelihood to sweat. 

3. Attachment

This is an extra step that allows the initial lust and attraction to crystalize into a lasting relationship, but not all flings will make it to this stage. For instance, one of the people involved may have commitment issues or be possessive and drive the other away. If you’re curious to find out your attachment style, you can take this quiz.

The presence of oxytocin and vasopressin makes attachment possible. Oxytocin, known as the “cuddle hormone” is released in the brain during the female and male orgasm to create attachment between the two people involved. Vasopressin, on the other hand, is known as the anti-diuretic hormone and is released after sex to strengthen attachment as well.

Some people don’t have as many oxytocin and/or vasopressin receptors, which is why they might have a harder time in getting attached to someone.

But does this all mean that love is simply a chemical process out of our control? Well, not exactly. Researchers say we can trigger our body’s chemistry into keeping love alive by keeping things fresh (novelty triggers dopamine), and touching (releases oxytocin).

Love might be more chemical than we thought.