5 Factors That Cause Chemistry Between Two People

What exactly is chemistry and how can you be sure if you have it with another person?

geeky hipster couple holding books and smiling at camera against blueprint wavebreakmedia / Shutterstock

People often talk about chemistry between two people in regard to romantic relationships but, until you’re in a relationship and really wondering whether this mystical theorem applies to you and your partner, it can be hard to pinpoint, describe or understand.

When people experience chemistry, it comes in all shapes and sizes, depending on what type of relationship you're referring to, such as romantic, platonic, professional, etc.


What is romantic chemistry?

Many people aspire to a perfect symbiosis between partners, where no one can argue that they exist in a supercharged realm of passion, connected to their soulmate.

Maybe that’s a bit rosy. Every relationship will have some highs and lows, but if the chemistry between two people is strong enough, the couple will recover quickly from the lows and enjoys even higher highs.

Based on her review of brain scan studies, biological anthropologist Helen Fisher, Ph.D., asserts that the initial feelings of intense romantic love "engage regions of the brain’s 'reward system,' specifically dopamine pathways associated with energy, focus, learning, motivation, ecstasy, and craving."[fn]Fisher HE, Xu X, Aron A, Brown LL. Intense, Passionate, Romantic Love: A Natural Addiction? How the Fields That Investigate Romance and Substance Abuse Can Inform Each Other. Frontiers in Psychology. 2016;7. doi:10.3389/fpsyg.2016.00687[/fn]


This phenomenon may be what many people are referring to when they talk about feelings of "chemistry."

And while there is no exact science as to what causes chemistry between two people (in spite of the fact that the phrase has the word “chemistry” in it), there are some attributes that relationships between two people with strong romantic chemistry will have.

RELATED: The Role Of Chemistry Between People In Real Love


Bear in mind that none of these qualities can be forced — they come naturally or they're cultivated. As with any relationship, communication and effort are essential to fostering growth and keeping chemistry alive.

As Clinical Hypnotherapist and Spiritual Life Coach Keya Murthy puts it, “You can’t fake it. If two chemicals will react with each other is part of the inherent quality of the chemicals. For humans too, it is just that. Either you two have romantic chemistry or you don’t.“

Five factors that cause chemistry between people

1. Mutual fascination

Chemistry is ignited when two people spontaneously spark a serious and intense romantic interest in one another. You could say they become fascinated with each other — yes, based on appearance — but also by something more. They often find they don’t run out of things to talk about because their captivation by one another goes far beyond your garden variety of conversational topics and pleasantries.

When there's romantic chemistry between two people, they will have a genuine interest and investment in what the one person thinks and has to say.


This phenomenon is all a part of “getting into each other’s heads.”

And the process by which partners get into one another’s heads begins with the next step: empathy.

2. Genuine empathy

Empathy is the ability to understand and share how another person is feeling. Many people are naturally empathetic toward all kinds of people in their day-to-day lives, whether it's toward family, friends, or even strangers (say, when striking up a conversation in line at the grocery store or in a waiting area) as well as toward their romantic partner. Some people display less empathy than others.

The kind of empathy between people with romantic chemistry[fn]Verhofstadt L, Devoldre I, Buysse A, et al. The Role of Cognitive and Affective Empathy in Spouses' Support Interactions: An Observational Study. PLOS ONE. 2016;11(2):e0149944. doi:10.1371/journal.pone.0149944[/fn] is a lot deeper than the usual sort of empathy anyone would ordinarily show, regardless of how abundantly empathetic or guarded they might ordinarily be.


Empathy for a partner runs so deeply in a relationship where romantic chemistry between two people exists that if one partner is emotionally hurting, the other will hurt right along with them.

If one partner is joyful, their partner will share in their joy. As time passes, this level of empathy will become practically automatic.

RELATED: The Real Difference Between Chemistry And Love

3. Instinctive emotional communication

As partners grow in their relationship and take steps to demonstrate their commitment to one another, such as moving with each together, they will be able to pick up on extremely subtle cues about how the other person is feeling.


As a sort of graduation from simply showing empathy toward each other, they will have learned much more about the other person by now and will naturally mirror one another’s feelings through their deeply-linked emotional connection.

They’ll often take on the burden of whatever stress or sadness their partner is experiencing instinctively. They will root for one another’s successes and be a shoulder to cry on when needed without ever really thinking about it or giving it a second thought.

Instinctively sharing one another’s emotions so closely and with such selflessness — by learning this special language of communication with each other that belongs only to them — should not be mistaken for an easy task. Strong relationships with chemistry that grows are all about putting in effort, time, thoughtfulness and care.

Partners who share romantic chemistry will also instinctively expend effort for one another. All of this comes from a place of love and desire to see the other person happy and fulfilled, all of which developed from those initial sparks that caused chemistry between two people.


4. Being in sync with one another

Being in sync consists of several things that very tightly-knit couples often do, such as: finishing each other’s sentences, knowing what the other’s thinking without having to say it out loud, adopting one another’s hobbies as if they were their own, communicating just about anything through body language, and so on.

Couples who have very strong romantic chemistry that truly bonds them have usually spent years cultivating the love in their relationship and will be totally in step with each other. This doesn’t mean that there won’t ever be friction or that they won't have disagreements.

Being in sync means always coming back, seeking love and an honest resolution, and staying on the same time and the same page.

RELATED: What Emotional Attraction Really Is (And Why Relationships Can’t Thrive Without It)


5. Physical attraction

This one should go without saying, but it's worth mentioning that this attraction is deeper than what just a superficial initial impression might spell out.

Most of us find lots of people physically attractive but that doesn't just have to do with looks.

Sexual attraction between two people will be about all of the physical qualities of each partner and the intimate familiarity that comes with two people being the right people coming together at the right time and the right place. They respond to each other's bodies in such dynamic, adrenalizing ways that are distinctly different from the interactions those people have had with others.


Can other people see the chemistry between two people?

When people think of the optics of a relationship, they often think of PDA or even wild, passionate strife. But chemistry is also easy to recognize — if you know what you're looking for.

When people have a lot of romantic chemistry, they might finish each other's sentences or just always seem to be on the same page.

They'll think and talk about each other even when their partner isn't around. They'll feel each other's feelings and share the same sense of humor — naturally, without having to work at it and fight over it.

Once you understand the fundamental elements of what causes chemistry between two people, it's plain to see — and share.


RELATED: What Happens To Your Brain On A Chemical Level When You Fall In Love?

Dan O'Reilly is a writer who covers news, politics and social justice.