This is part 8 of a series on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the introduction here.
“we are never so defenceless against suffering as when we love, never so helplessly unhappy as when we have lost our loved object or our love.” – Sigmund Freud (Civilization and Its Discontents)
One of my more vivid memories from early childhood is of Tammy and her two friends. I was about 6 years old, and in the first grade. They were third graders, a couple of years older. By coincidence, our two classes had arrived simultaneously at the hallway outside the girls’ lavatory. In those days, teachers took their entire class to ‘the lav’ for efficiency’s sake, and every day the boys finished our business promptly then lined up in front of the teacher as we waited for the girls to finish theirs. On that day, our schedule happened to align with grade three.
I can still remember Tammy looking at the note I had written her, passed along by a friend, with her friends on either side. Exactly what I wrote is lost to time, but I recall the romantic sentiment behind it and drawing a picture of a boy and a girl kissing. Today, such behavior (or going even further) could actually get a young child suspended from school.
What compelled me to write the note, I don’t know. I do remember that Tammy seemed kind and pleasant to look at, and that it felt right – even at that age – to try to express it. However, that feeling quickly turned to embarrassment, when she and her friends waved, laughed in unison, and –in sing-song fashion – said “Hi, Patrick.” We were all just kids and no harm was intended, but at that point, I wanted to hide. And, though I can’t remember this part very well, I probably wondered why the third grade teacher was so slow in taking her students back to class.
It wasn’t clear where I went wrong, but my interpretation of Tammy’s behavior was that my private feelings of attraction, which came pretty easily, somehow violated the rules. Early experiences carry a lot of weight, and that incident taught me that revealing private emotions was a risky endeavor. It’s tempting to want to hide them away. 
With Valentine’s Day just behind us, I wanted to develop on some of the elements in this innocent story in a couple of posts (update: part 9 here), such as where attraction and its hypertrophic cousin, romantic love, originate, and even why they might show up in early childhood. The other element is the more negative aspects of romantic pursuits, which extend well beyond the embarrassment of childhood puppy love and into profound despair and suffering. Perhaps the cynics have good reasons to feel that it is somewhat myopic to give love its own day to be celebrated while glossing over the countless people it has wounded over the millennia. Homer Simpson, in his toast to inebriation, once referred to alcohol as “the cause of, and solution to, all of life’s problems.” I don’t think too many people would object if we replaced the word ‘alcohol’ with love. So, what is this thing that nature has given us?
I think it’s important to look at the biology of romantic love to get a fuller understanding of it. Part 5 of this series examined some of the arguments for why pair-bonding and the intensity of early-stage romantic love (also called passionate love, limerence, or infatuation) might have evolved in humans. Helen Fisher suggested that romantic love likely occurred early in human evolution for its “timeless purpose of weeding out unsuitable mates, focusing one’s attention on a ‘special’ other, forming a visible pair-bond with this beloved, and remaining sexually faithful to ‘him’ or ‘her’ at least long enough to conceive a child together” (2004: 215).
Fisher also referred to romantic love as occupying a position near “the pinnacle” of all human emotions and drives (2004: 98), and that it was at least somewhat biologically independent from sexual desire and a more mature, but less intense, ‘companionate’ love. In a meta-analysis of twenty published fMRI studies, Cacioppo et al. (2012) concluded that romantic love, which they defined as “a state of intense longing for union with another,” had a highly overlapping “shared brain network” with sexual desire. At the same time, specific dopamine-rich brain regions were more active in love (ventral tegmental area, dorsal right striatum), while others were more active in sexual desire (ventral striatum, hypothalamus, amygdala, somatosensory cortex, inferior parietal lobule). Compared to desire – described as a very “specific, embodied goal” – they viewed love as a “more abstract, flexible, and behaviorally complex goal that is less dependent on the physical presence of another person” (p. 1052). There are other specific brain regions and neurotransmitters involved I didn’t mention above, but the upshot is that desire and love are overlapping but independent, and complex. How could it not be complex? It’s human behavior.
One more detail: Cacioppo et al. noted the brain regions involved in love were involved not only with motivation and reward expectancy, but also ‘habit formation.’ Around the time the article was published, one of the authors, Jim Pfaus, said that love “works the same way in the brain as when people become addicted to drugs.” That theme of addiction recurs in many scientific descriptions of romantic love. In their book “Welcome to Your Brain,” Sandra Aamodt and Sam Wang playfully wrote that “love may be the original addiction” (2008: 127). It may not be a perfect analogy, but it overlaps enough to help us understand why love may often be a painful experience, as we’ll see.
Problems with Darwinian Explanations
Not everyone likes this approach. In an essay titled “Where Do We Fall When We Fall in Love?,” the late psychoanalyst Elisabeth Young-Bruehl lamented that:
“contemporary Darwinians have had no trouble taking the mystery out of romantic love. They tell us that when we fall in love we are falling into a stream of naturally occurring amphetamines running through the emotional centers of our very own brains… Eventually, our nerves being what they are, their endings become amphetamine immune or exhausted, and the delirium of our free fall abates. We come down to earth” (2003: 279).
We can quibble with this description of the biology of romantic love, but the overall thrust of Young-Bruehl’s argument – that we should be wary of reductionist explanations – is warranted. She also suggested that the search for evolutionary explanations was spurred by the poor current state of love relations in the United States, since she saw that country as where Darwinian ideas on love took flight. She saw a desire to naturalize “how we are hard-wired for passion, for attachment or marriage, and for divorce… it is our nature, in the form now of natural amphetamines, that must be fought. We must mount a war on our body’s drugs. Just say no.”
Again, Young-Bruehl’s point that our behavior is more complex than any single cause is a valid one. But I disagree with the notion that Darwinian explanations take the mystery out of love (or biology in general). Certainly, Darwinians can (and do!) fall in love. They are no more immune to it than pharmacists are to morphine. I also have doubts that current love relations in the United States are uniquely poor, as people throughout history and across cultures have had some level of romantic turbulence.
Finally, I don’t think that a attempting to understand the biology of love should be seen as attempt to naturalize the status quo. As Cacioppo et al said, love is “flexible,” and it need not rigidly follow Fisher’s evolutionary scenario of a person bonding with a mate for the sole purpose of reproduction. It almost certainly did evolve for something like those reasons, but people from all sexualities fall in love, as do the elderly or hetero couples with no intention of procreation, or even well before reproductive maturity, possibly even into childhood (for a review of precocious “first loves” see Janssen 2008). It is also possible for three or more people to love each other.
Still, there are good reasons to look to biology and evolution, and anthropology, to help us understand love and the turmoil it sometimes causes. Though we won’t get all our answers there, every tool helps. However it first evolved, at this point we can be fairly certain that romantic love is a real phenomenon for a couple of reasons. First, the neurobiology of love described earlier correlates with a consistent suite of bio-behavioral features, including: obsessive ‘intrusive thinking’; idealization of the other person; sleeplessness and loss of appetite; and feeling that intense romantic love is ‘involuntary’ (see Part 5 for more). Secondly, it has been found in about 90% of cultures surveyed, suggesting it is a nearly universal occurrence in our species, though cultural influences certainly affect how it will be interpreted (Jankowiak 2008).
Some have contended that because arranged marriages were the norm in many parts of the world, romantic love must have been invented (quite possibly by the French). Of course, love and marriage are not the same thing, and the points above strongly suggest that the French didn’t ‘invent’ love, just as the Irish didn’t save civilization. In parts of the world where arranged marriages are still common, romantic love is not absent. In India, for example, love commandos offer sanctuary to young people who have fallen in love against their family’s wishes. If we did have any single group to thank for romantic love, it might be a good idea to request an upgrade to take some of the bugs out.
We’ll get to those in Part 9 (Love is an Evolutionary Compromise).
Aamodt S, Wang S. 2008. Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life. Bloomsbury. Link
Cacioppo S, Bianchi-Demicheli F, Frum C, Pfaus JG, Lewis JW. 2012. The common neural bases between sexual desire and love: a multilevel kernel density fMRI analysis. Journal of Sexual Medicine 9(4): 1048-54. Link
Fisher H. 2004. Why We Love: The Nature and Chemistry of Romantic Love. Putnam. Link
Freud S. 1930. Civilization and Its Discontents. Norton. Link
Jankowiak W. 2008. Intimacies: Love & Sex across Cultures. Columbia Univ Press. Link
Janssen DF. 2008. First love: A case study in quantitative appropriation of social concepts. The Qualitative Report 13(2): 178-203. Link
Young-Bruehl E. 2003. Where do we fall when we fall in love? Journal for the Psychoanalysis of Culture and Society 8 (2): 279-288. Link
 There is a beautiful letter from Ted Hughes to his son on how we hide our authentic selves under a layer of armor, and how the cost of this is isolation and making ‘no contact’ with others. “The only calibration that counts is how much heart people invest, how much they ignore their fears of being hurt or caught out or humiliated. And the only thing people regret is that they didn’t live boldly enough, that they didn’t invest enough heart, didn’t love enough. Nothing else really counts at all.”