Eyes meet as both characters move in. After an hour of longing, flirting, fighting, and reconciliation—of which you’ve spent the last 20 minutes on the edge of your seat—it happens…. That out-of-the-ballpark, incredibly satisfying, perfect first kiss. Fireworks ensue.
It’s the stuff of movie magic, the moment we’re always waiting for, and the climax of every great love story. Even when we know it’s coming, we still feel exhilarated watching two characters we care about finally lock lips. And fortunately, the feelings associated are not a cinematic special effect or the result of mood lighting set to a romantic score. When there’s real chemistry involved, the right kiss can be even more spectacular than the movies portray, thanks to a cocktail of hormones and neurotransmitters that course through our brains and bodies as a result.
Of course, sometimes, a kiss can have a very different effect. Remember that scene in Back to the Future, when Lorraine grabs her time-traveling son Marty for a passionate kiss only to recognize her romantic feelings instantly disappear? “When I kiss you,” she admits, “It’s like I’m kissing my brother.” When kissing chemistry is all wrong, both partners have ways to sense they should back off. Kissing can provide clues about when a match is star-crossed, or even poorly suited genetically by putting us in very close proximity to sample scent and taste. According to evolutionary psychology research, 59 percent of men and 66 percent of women report having ended a budding relationship because of a bad kiss. In this manner, the act of kissing is nature’s ultimate litmus test.
But when two people are well-suited, nothing beats that special exchange. In our favorite fairy tales, it has the power to turn a mermaid into a human, a frog into a prince, or break an evil witch’s spell. In our own lives, a good kiss can surprise us and even start something special with the person we least expect. Our cheeks flush, pulses quicken, and breathing can become irregular. Pupils dilate which may be why so many of us to close our eyes. We engage all of our senses in the activity—consciously and subconsciously—to gather information about compatibility, sending a cascade of information to our brains. From there we decide whether to take things further and pursue a relationship.
In a well-suited match, kissing is associated with a rise in a chemical called dopamine, which is responsible for feelings of craving and desire. Some people who pump lots of dopamine lose their appetites or report they cannot fall asleep. Meanwhile, oxytocin leads to strong feelings of attachment as we form a special bond with someone else. It can also seem impossible to stop thinking about the other person because of a spike in serotonin, which causes obsessive feelings and thoughts. In fact, serotonin levels during a budding relationship can rival those of individuals suffering with obsessive-compulsive disorder (OCD). In other words, a kiss is a powerful experience and acts like a natural drug. The novelty of the exchange stimulates the same pleasure centers in the brain as a line of cocaine.
Notice anything? The body’s chemical response to kissing mirrors many of the same feelings frequently associated with falling in love—including the symptoms experienced by our favorite on-screen characters such as Allie and Noah in The Notebook, Jack and Rose in Titanic, Bella and Edward inTwilight, and Ennis and Jack in Brokeback Mountain. When the moment is right, both on and off screen, it can be absolutely unforgettable.