I’ve been dating since I was 14. I’ve gotten involved with lawyers, artists, entrepreneurs and perpetual students. I’ve dated a man from every continent and too many countries to list. I’ve fallen for guys because they had a way with words and had relationships that, due to language barriers, were limited to gestures and a handful of poorly pronounced phrases. With so many people out there, how do these love connections happen? According to one researcher, the answer lies in our biology.

Helen Fisher, Ph.D., a noted anthropologist, has studied the science behind romantic love for more than 30 years. She categorizes people into four basic personality types: Explorers (motivated by dopamine), Negotiators (estrogen), Directors (testosterone) and Builders (serotonin). Fisher explains that we instinctively seek out partners whose chemical makeup complements our own. One focus of her work is on the link between love and dopamine, a neurotransmitter that controls the brain’s pleasure center.

Fisher found that couples who engage in new activities together tend to create a stronger connection. The thrill of novelty leads to a dopamine rush that activates feelings of elation and focused attention, which bodes well for romantic relationships.

After taking Fisher’s personality test, I learn that I’m an Explorer with Negotiator tendencies. Explorers are spontaneous, curious and open-minded, while Negotiators tend to be intuitive, trusting and empathetic. So it’s little surprise that my greatest love affair began when a stranger asked me to lunch under the guise of introducing me to “an amazing new restaurant.” How could an Explorer say no to that? (I blame my Negotiator side for even entertaining conversation with a stranger in the first place). Weekends often found us on a train or plane bound for a new destination, such as ATVing in the Greek Isles to discover sleepy villages off the beaten path.  Life circumstances ended our romance, but he remains a dear friend (and favorite travel partner) to this day. What I loved most is that we never stopped having fun. Sure, we had our fair share of disagreements, but at the end of the day, we simply enjoyed being in each other’s company.

That’s the common thread Fisher found in happy couples: The dopamine center in their brains lit up at just a mention of their beloved’s name. Even after decades of marriage, they never lost that spark of excitement. Isn’t that what we aim for—to feel a thrill for our spouse long after the day-to-day routines of partnership have set in?

Fisher calls romantic love “a universal experience, deeply embedded in the human brain.” I like that idea. Biology plays its part, but in order for the love experience to be a fulfilling one, there has to be a mutual desire and ability to have fun together, to be constantly learning and growing—individually and within the confines of the relationship. I believe timing and fate factor into the equation, too. So when everything comes together, you have the recipe for a successful partnership—dopamine rush included.