Love at first sight is hard to explain. Some people swear they’ve fallen prey to its mystical power (sometimes more than once), while others chalk it up to folklore and too many viewings of Baz Luhrman’s Romeo & Juliet (or reading Shakespeare’s original, though far less common). We tend to gravitate towards the latter category, being the doubting, scientific-minded realists we are, but recently, we came across a fascinating study from researcher Stephanie Cacioppo titled Neuroimaging of Love: fMRI Meta-Analysis Evidence toward New Perspectives in Sexual Medicine. Cacioppo (whose last name was Ortigue at the time) led a team of researchers who examined exactly what occurs in the brain when you fall in love and lust. Some crazy findings right off the bat? Twelve—yes, twelve—areas of your brain work together to release chemicals and hormones that induce the feeling of falling in love, all of which happens in just a fifth of a second, which elicits floating-on-cloud-nine feelings similar to that of euphoria-inducing drugs (though there are key differences, which we’ll explain later). Yeah, we’ll let you process that for a second.
Because we found the study and science behind love so fascinating, we stalked Dr. Cacioppo and asked her to explain everything in further detail for us. (You’re welcome.) Keep scrolling to find out the science behind falling in love!
We all recognize the telltale signs of falling in love—butterflies, the sudden urge to talk in a baby voice, obsessive thoughts, separation anxiety…oh, just us? Anyway, Cacioppo says that love carries many definitions, but the one used nowadays in science “characterizes love not only as a basic instinct and emotion, but also a complex psychological emotional mental state which involves four dimensions.” Those four dimensions are: chemistry, cognition, preference/ rewarding mechanisms, and an intention to be with a significant other.
Cacioppo cites a study by Hatfield & Rapson from 1987, which says that passionate love is defined as “a state of intense longing for union with another,” that is characterized by a “motivated and goal-directed mental state.” What exactly does that mean? Basically, she’s saying that if you were to describe the concept of falling in love, it would be “the awareness of being in love” with someone. “Our research on love suggests that love is a two-stage process, the first of which is sub-conscious,” she explains. “Based on our findings on love, we make the hypothesis that the concept of falling in love could correspond to the awareness (consciousness) of being in love with someone.” So—the first part is sub-conscious, but the actual process of falling in love requires you to actually be aware of what’s happening. Which takes us to our next point…
Here’s the thing—it’s hard to describe exactly what happens in the brain during the phenomenon of love at first sight, because that would require a scientist to be able to record someone’s brain activity when it happens. Not likely. However, Cacioppo says you can make hypotheses about the brain areas that come into play—but first, you have to differentiate the brain areas involved in lust vs. love. Ready? This is where it starts to get a bit more complicated.
“Desire for someone is defined as an increase in the frequency and intensity of sexual thoughts and fantasies, either spontaneous or in response to erotic stimuli,” Cacioppo says, quoting from a study by psychiatrist Rosemary Basson, M.D. “Desire corresponds to a basic instinct/emotion and a complex psychological emotional mental state which involves, like passionate love does, three dimensions: 1) chemistry, 2) cognition, and 3) preference/rewarding mechanisms.” Sound familiar? Yes, those are the exact same dimensions Cacioppo mentioned earlier when it came to describing love—but unlike lust and desire, love has a fourth dimension: the intention to be with one significant other. In other words, love is different from lust because you actually have to desire to be with just that person. Let’s take this even further, and examine what differentiates love and lust in the brain.
“Overall, fMRI studies demonstrate that both passion and sexual desire spark increased activity in the subcortical brain areas that are associated with euphoria, reward, and motivation, as well as in the cortical brain areas that are involved in self-representation and social cognition,” Cacioppo says, quoting her own study from 2012. We won’t get into all the technical terms and areas of the brain, but we’ll just say this: there are a lot of areas of the brain that respond similarly when measuring lust and love. However, when it comes to measuring love vs. lust, activity is diminished in the ventral striatum, hypothalamus, amygdala, somatosensory cortex, and IPL. What exactly does that imply? Cacioppo says that these reductions are in line with the idea that sexual desire and lust is a motivational state with a very specific, embodied goal, while love is a more abstract, flexible, and behaviorally complex goal that is less dependent on the physical presence of someone else.
Ready to go even deeper? Let’s examine how love makes you feel the giddy feelings you do. Cacioppo says love is associated with a more intense activation of dopamine-rich regions in your brain, generally involved in motivation, reward expectancy, and habit formation. This is in line with psychological studies that define love as a rewarding, positive, and motivating experience. Also, different parts of your brain are activated by feelings of love rather than sexual desire, which Cacioppo says is in line with the fact that love is an abstract construct, “partly based on the mental representation of past emotional moments with another.” Whoa—what? She explains: “This specific pattern of activation suggests that love builds upon a neural circuit for emotions and pleasure, adding regions associated with reward expectancy, habit formation, and feature detection.” She says that the way your brain shows love and lust suggests that love grows out of and is a more abstract representation of the “pleasant sensorimotor experiences” that characterize desire. The final conclusion? Basically, you can see love and lust on a spectrum, with love growing from the visceral sensations of lust into a complicated, ultimate feeling incorporating everything from reward expectancy to habit learning. Whew! Love is a many splendored thing, no?
Now that we’ve examined the effect love has on your brain, what about that beating organ in your chest? According to Cacioppo, it makes perfect sense why your heart would be associated with feelings of love. “Because love is a powerful mental state that has different physiological manifestations, like butterflies in the stomach or in the chest, increase heart rate, euphoria, loss of appetite, hyperactivity, loss of self-control, and a decrease need for sleep*, it comes to no one’s surprise that the origin of love has often been associate with the organ that is generating such a physiological response.”
*Aron et al., 2005; Buss, 2003; Sternberg & Barnes, 1988; Hatfield & Walster, 1978
Remember how we mentioned earlier that love can triggers activity in areas of the brain similar to euphoria-inducing drugs? Well, Cacioppo makes it clear that love is actually quite different from drug addiction because it “recruits higher-order brain areas involved in complex functions like emotion, reward, goal-directed behavior, and decision making.” As she explains, “Love is one of the deepest forms of human endeavor. Although love partly activates some of the brain areas that are also activated during drug addiction, love is so more than an addiction.”
Do you believe in love at first sight? How do you think love differentiates from lust? Sound off below!