The really cynical people in the world like to say that love is just a chemical reaction that compels animals to breed and then think to themselves how logical and scientific they are. These people also tend to be in high school or just happen to be very lonely individuals. Either way, science is not that clean-cut about the topic of love. So, in acknowledgment that Valentine’s Day is just around the corner, let’s see what science has uncovered so far about humanity’s oldest and most hackneyed phenomenon.
Usually when the word love is brought up in a scientific setting, most people refer to the rules and reasoning behind romantic attraction: what physical properties makes a person desirable. In regard to physical attractiveness, many researchers have concluded that symmetry plays the biggest role, a claimed backed by numerous studies and years of investigations. Scientists have found that this measurement of beauty holds true across various cultures and even in different species of animals (The Telegraph, “The Science of Sexiness: Why Some People are Just More Attractive,” 04.08.2015).
The general consensus appears to be that having a symmetrical-looking face serves as a good indicator of robust health and ideal genes, which prospective romantic partners subconsciously pick up on. Psychologist at Brunel University in the United Kingdom Dr. William Brown remarks, “In animals with two sides that were designed by natural selection to be symmetrical, subtle departures from symmetry may reflect poor development or exposure to environmental or genetic stress. In many species, these departures are related to poor health, lower survival, and fewer offspring” (National Geographic News, “Symmetrical Bodies are More Beautiful to Humans,” 08.18.2008).
Interestingly, there has been some pushback against this consensus in recent times. Artist and photographer challenged this notion of symmetry as attractive by creating portraits of models whose faces have been photoshopped to be mirror images of the left and right sides of their faces (Time Magazine, “Here’s What Faces Would Look Like If They Were Perfectly Symmetrical,” 06.09.2014). In a study performed by Nicholas Pound, another psychologist from Brunel University, results showed that facial symmetry in adolescents did not correlate with rates of childhood illness, as many researchers presumed (The Economist, “Facing the Facts,” 08.16.2014). However, the most interesting counter-argument insists that the perfect face doesn’t stem from symmetry but from the Golden Ratio, an ancient Greek mathematical ratio of 1.618:1 that has been observed in the proportions of flowers, spiral galaxies, famous Greek art and attractive faces (The Golden Ratio, “Beauty, the Perfect Face and the Golden Ratio, featuring Florence Colgate,” 09.01.2013).
But beyond just physical appearances, science has found other explanations behind why one person would fall in love with someone. For instance, how you smell could determine who you attract, that is to say, the pheromones you emit. Widely used in the Animal Kingdom, pheromones are scent-bearing chemicals that we secrete in sweat and other bodily fluids that influence the behavior of others. Humans also utilize pheromones and researchers believe that these chemical signals play an important role in sexual attraction (The Huffington Post, “The Strange Science of Sexual Attraction,”02.20.2015). In one study, researchers found that women who smelled sweaty undershirts worn by men could accurately judge their attractiveness. In a different study, researchers from the University of Texas at Austin discovered that men could determine when a woman was at her most fertile period in her menstrual cycle based on her pheromones. When these men were asked to smell T-shirts worn by women, they judged the shirts worn by fertile women to be more “pleasant” and “sexy”–ugh, creepy (The Huffington Post). In both cases, it’s likely that these types of scent detection happens subconsciously.
However, it is important to note that the research into human pheromones is still incomplete. Researchers have yet to identify specific chemical compounds that spark physical attraction in people, at least not any with a reliable scientific foundation. The closest they got was with androstadienone, a steroid derived from testosterone that has been reported to “make women feel more relaxed” (Scientific American, “Do Pheromones Play a Role in Our Sex Lives?,” 02.12.2012). But the lack of solid evidence hasn’t stopped the perfume industry. You can find all sorts of “pheromone-based” perfumes on the Internet that claim to attract the opposite sex. The more expensive, popular ones have countless positive reviews that praise its effectiveness, but I’m more inclined to believe that this is because of the placebo effect.
There are also theories floating around that romantic attraction is largely guided by genetics and the goal of finding a mate who will help produce healthier offspring. For instance, researchers from the University of Western Australia suspect that a person’s body odor could provide clues about that person’s immune system (NY Daily News, “Secrets of Attraction May Lie in Immune System DNA That’s Sensed Through Sweat,” 02.17.2010). According to their study, a woman’s sweat contains chemical information about her histocompatibility, or MHC, genes. This information also subconsciously notifies embers of the opposite sex about the type of immune system she has. To the researchers’ surprise, not only did the female participants with the most varied MHC genes appear more attractive to the male participants, but they also had the greatest number of sexual partners (NY Daily News). This is most likely because a person with varied MHC genes also has a diverse immune system, a trait associated with disease resistance.
So far, all these research studies seem to push the notion that romantic attraction is mainly outside of our control, which may dishearten several readers. However, all these studies have another common thread: They’re about infatuation, not love.
Everything from facial symmetry to pheromones to histocompatibility genes focuses on the love-at-first-sight aspect of romance, the instantaneous physical attraction that occurs when two people meet for the first time. These factors might answer why you have a premature crush on someone but say nothing about what helps a relationship survive conflict or last for a long time. Just because two people are biologically compatible doesn’t mean that their personalities will mesh well. How regrettable that science is not invulnerable to the “love at first sight” mentality that plague movies and literature.
Of course, I’m exaggerating: There are obviously some studies focused on maintaining a relationship, not just infatuation. However, the little that I could find was surrounded by an ocean of research on the immediate sensation of falling in love. That’s not surprising, since falling in love is easy and fun, while keeping a relationship together is stressful and aggravating. But even though your DNA or your immune system or your pheromones might determine who you choose as your significant other, those biological factors change over time. What will happen when you’re no longer biologically compatible with your partner? Ultimately, one must make an effort to truly understand the other person’s personality and values and build a foundation of trust and friendship beforehand. Science may explain what gives love its sparks but it can’t provide any real shortcuts.