Someday My Prince Will Come: The Science of Love

Like most typical girls, I grew up watching Disney movies, which consisted primarily of princesses finding their true loves and living happily ever after. I watched these movies and played “house” while thinking to myself that one day I would find my own prince charming, and live happily ever after just like the princesses I grew up admiring. In addition to the Disney movies that initiated my thoughts of finding true love, learning about the concept of “soul mates” added to my belief that I was destined to be with someone. Plato presents a theory of soul mates in his philosophical dialogue, Symposium. He describes humans as originally having four arms and legs and a single head made of two faces, but Zeus divides them in half because he is afraid of their power [6]. Plato and Disney movies comprise a small fraction of the vast number of cultural sources that reference the concept of romantic/coupling love and soul mates. This specific conceptualization of love, the idea that each individual human has an emotive/physical/spiritual connection to one other human, is ubiquitous in human culture. However, after twenty years of waiting to be whisked away by a handsome, young prince of my own, I have extinguished my childhood fantasies and decided to see if this thing called love can be scientifically explained, for the purpose of helping hopeless, lost believers of old fairy tales in the task of understanding love in an empirical and methodical framework: to help shed its dark, mysterious mask.  

The unmasking can start with defining romantic/coupling love as a trait. Love can be viewed as a behavioral pattern that has persisted in the human species throughout its history. Given love’s long-term presence in human history, it seems reasonable to conclude that it must have played a role in past human survival. With any trait that appears from one generation to another, those traits that are advantageous in an environment are favored for reproduction in future generations (an evolutionary mechanism called natural selection). The prevalence of romantic/coupling love across cultural and geographical boundaries implies that love is biologically rooted in the human species.  It is important to recognize love as a biologically rooted trait that has managed to survive throughout the whole of human history because such recognition allows for scientific study.

Dr. Helen Fisher, a Biological Anthropologist who is a research professor at Rutgers University and Chief Scientific Advisor to the internet dating site, chemistry.com explains the biological purpose of love: to help with reproduction, which will perpetuate the human species.  She defines love in three stages: lust, attraction, and attachment. By her definition, lust (the sex-drive) evolved to get people looking for mates, romantic love (the obsessive thinking that occurs when one falls in love) evolved to enable one to focus on just one individual thereby conserving courtship time and energy, and attachment (the feeling of security) evolved to enable one to stay with the chosen individual to raise children together [2]. Love is imperfect and far from what Disney princess movies and Plato make it out to be since the three stages of love can work independently and simultaneously, and allow for people to fall in love with multiple people. According to Dr.Fisher, people can feel deep attachment for a long-term spouse, while they can feel romantic love for someone else, while they feel the sex drive in situations unrelated to either partner. Dr.Fisher nicely sums up love and its consequences, “We were not built to be happy but to reproduce” [3].

Love has been observed and studied by researchers and it has shown connection to the activation of various parts of the brain and presence of particular hormones and neurotransmitters within the brain. Dr. Helen Fisher conducted a study in which she studied the brains of 17 “newly in-love” college students using functional magnetic resonance imaging (fMRI), which shows activities in parts of the brain by measuring blood flow. The subjects were shown a picture of a friend and of their partners while their brains were under observation via fMRI. The study showed that the ventral tegmentum, the part of the brain responsible for pleasure, addiction, motivation, sleep, mood, attention, and learning, was activated when they saw the picture of their partners. The ventral tegmentum consists of high concentrations of dopamine, a type of neurotransmitter, receptors which explain the responsibilities associated with that region such as addiction [1]. The fMRI findings thusly make sense since people find love addictive, e.g. they cannot help but think obsessively about their significant others.

In correlation with the high activity of dopamine, there is low activity of serotonin, which is involved in modulation of anger, aggression, body temperature, mood, sleep, human sexuality, appetite, and metabolism. The low activity of serotonin also explains some of the symptoms of love, such as sleeplessness and decreased modulation of anger and aggression [5]. I specifically remember when I witnessed such symptoms of love when I visited a friend in Swarthmore and bore witness to a couple of guys fighting intensely over a girl. Their lack of modulation of anger and aggression could be explained by their low activity of serotonin.

Dr.Helen Fisher’s findings strengthened the findings from an earlier study done in 2000 by Andreas Bartels and Semir Zeki of University College, London. This study also located parts of the brain activated by love using fMRI to monitor the reaction to certain stimuli by students in a relationship. The study revealed that the ventral tegmentum (refinery for dopamine, which regulates reward) is activated in those students engaged in a love based relationship [7]. In addition to the two studies, Acevedo, who works at the Albert Einstein College of Medicine in New York isolated regions of the brain, which some researchers believe form a “circuit of love” including the following: the ventral tegmentum area (VTA), the nucleus accumbens, the ventral pallidum and raphe nucleus. The findings showed the VTA was activated in newly in-love people, but that it was also activated in people in love after 20 years. In the people who were in love after 20 years, two more areas of the brain were activated: the ventral pallidum and raphe nucleus. The ventral pallidum is associated with attachment and hormones that decrease stress. The raphe nucleus pumps out serotonin resulting in a sense of calm [4]. Activation of the ventral pallidum and raphe nucleus explains the longevity of a relationship. People in long-term relationships are rewarded with the activation of these regions in the brain, de-stressing and calming them. The parts of the brain associated with love explain the good feeling many people in love have, making love seem magical.

In addition to the ventral pallidum and raphe nucleus, hormones called oxytocin and vasopressin are also involved in the long-term commitment stage of love. These hormones are associated with reward and reinforcement regions of the brain. It is believed that animals form strong social bonds because of the location of their receptors for vasopressin and oxytocin [3]. Since oxytocin and vasopressin receptors are found in reward and reinforcement regions of the brain, these hormones allow people to form bonds strong enough to last a long time.

Given that chemicals and hormones in people’s brain can create a sustainable love, which people may call true love, these chemicals and hormones can also work to create love that is not so sustainable. For example, these chemicals and hormones can be produced due to adrenaline in a crisis, such as an emergency landing of an aircraft, making individuals believe that they have found their “soul mate”. Jim Pfaus, a psychologist and sex researcher at Condordia University in Montreal related such incidences with people meeting and dating under the regular influence of drugs and or alcohol. In both cases, hormones and natural opiates are activated creating good feelings and people associating those feelings with the person present. “You think someone made you feel good,” Pfaus says, “but really it’s your brain that made you feel good” [7].  Incidences where people mistake good feelings created from drugs and or alcohol with having found their “soul mates” occur frequently in colleges and universities, where students frequently attend fraternity parties that promote heavy drinking. Perhaps, Pfaus’s statement can be of assistance to college students pondering about the amazing connection they had made with someone at a party.

I have tried to explain the wonder of love in terms of scientific observations and correlations generated by researchers. My exploration resulted in the idea that love is enchanting because our brains make it so. With this idea, people can become more educated about what love consists of and that it is not as mysterious and magical as Plato and the Disney movies portray it to be. True love and “soul mates” do exist if you define them to be long-term relationships due to activation of various regions in the brain and hormones. Since love involves activation of various regions in the brain with different levels of neurotransmitters and hormones, can we alter these different levels and ultimately make people fall in and out of love? It is very likely that this question will be answered in the near future as scientists dig more deeply into brain’s involvement in love.

In another note, through this research, I have learned that the term love is used broadly to describe various stages of love, such as lust, attraction, and attachment, but is this appropriate? Does the empirical evidence relating to love explain our loose usage of the term love? It is difficult to distinguish if our biology has affected our usage of the term love or if our usage of the term love has muddled research in specifically designating/clarifying love.

References

[1] Dopamine -. (n.d.). In Wikipedia, the free encyclopedia. Retrieved April 6, 2009, from http://en.wikipedia.org/wiki/Dopamine

[2] Love's Chemical Affair. (n.d.). In Soul Mate Express. Retrieved April 6, 2009, from http://www.soulmate-express.com/2009/01/loves-chemical-affair.html

[3] Oxytocin, chemical addiction and the science of love. (n.d.). In Oxytocin . org : the biology of true love. Retrieved April 5, 2009, from http://www.oxytocin.org/oxytoc/love-science.html

[4] The science of romance: Brains have a love circuit. (n.d.). In Arizona Local News - Phoenix Arizona News - Breaking News - azcentral.com. Retrieved April 6, 2009, from http://www.azcentral.com/offbeat/articles/2009/02/11/20090211lovescience-ON.html

[5] Serotonin -. (n.d.). In Wikipedia, the free encyclopedia. Retrieved April 6, 2009, from http://en.wikipedia.org/wiki/Serotonin

[6] Symposium. (n.d.). In Azurnet. Retrieved April 6, 2009, from http://www.ac-nice.fr/philo/textes/Plato-Works/17-Symposium.htm

[7] Truly, madly, chemically in love: the finer points of romance - Times Online. (n.d.). In Times Online | News and Views from The Times and Sunday Times. Retrieved April 6, 2009, from http://www.timesonline.co.uk/tol/news/uk/science/article3341033.ece