Love: A Neurochemical Approach

"We were not built to be happy, but to reproduce."

-- Dr. Helen Fisher, Rutgers University

Do you believe there's one person out there for all of us? More to the point, do you define love as some sort of ethereal meeting of souls, or more as a mixture of chemicals in the brain inducing some sort of feel-good response? Is love a by-product of sex, a sort of trickery enacted on our glands by our brains to ensure the survival of our species through neurochemical intimacy? Or is love everything the poets say it is – enduring, consuming, and free from the constraints of the physical?

Let me backtrack a little. Before you get any ideas, I'm not going to spend this episode attempting to convince myself and the world at large that love doesn't exist just because it hasn't come through for me thus far – obviously it exists, there are numerous examples of love dating back to the dawn of recorded human history. Some of the first examples of early writing are in fact love poems, which indicates that the human propensity for goo-goo eyes, sappy sentimentality and marriage is a trait we probably had on our emergence from the primordial soup. The question is, WHY does it exist? What function does love serve and why did it evolve in the first place? Social monogamy serves a distinct biological purpose, so no surprises why it arose -- and before you try to argue that monogamous pair-bonding is an unnatural state enforced on modern man by a judeo-Christian ethic, think again. Pair-bonding in humans predates Christianity. In point of fact, pair-bonding is common in most primates, especially in primates like Chimpanzees, Bonobos, and well, us, that are not especially sexually dimorphic. Gorillas, which exhibit a high degree of sexual dimorphism, have harems. The male gorilla (the silverback) has his little troop of female gorillas that he guards jealously from the sexual advances of any other male gorilla in the vicinity. Chimps, on the other hand, are more like us – everybody gets it on with everybody else. Keep in mind that there is a difference between social and sexual monogamy – for the purposes of this essay I'll assume they're the same, but they aren't. No mammal is truly sexually monogamous.

Unlike many pair-bonding species in the animal kingdom (birds mostly – see the Osprey, which should serve as a model for all couples), humans aren't truly monogamous (a sad fact bemoaned by cuckholded partners everywhere) but rather engage in serial monogamy with extra-pair affairs. The scientific theory behind this is that promiscuity ensures genetic diversity in small groups – but that increased group size among human populations leads to a rise in sexually transmitted diseases (also not a new phenomenon) which curbs promiscuity. So humans live in a sort of sexual gray area, where we are primarily monogamous but occasionally promiscuous – ensuring genetic diversity while at the same time avoiding STDs. "But Sunny," you're saying, "you're talking about sex here, not love! There's a difference." Au contraire, gentle reader, is there really?

Human behavioral scientists have isolated three stages of love and the accompanying hormones that drive them.

Stage 1: Lust

You can't love somebody unless you want to jump their bones first. Testosterone and Estrogen, the hormones which fuel the baby-makin' urge, are responsible for this stage.

Stage 2: Attraction

This is the cutesy, googly-eyed stage that so annoys your friends and roommates. The chemicals involved here are dopamine (cocaine & chocolate affect the brain in the same way – in fact MRIs of people in love look more similar to coke addicts than anything else), adrenaline (responsible for sweaty palms and heart palpitations) and serotonin, the neurotransmitter that makes us go temporarily insane. People in love have been found to have extremely low levels of this chemical in their brains – a state similar to that in people with anxiety, depression, and obsessive-compulsive disorder. Obviously people in love need to be dosed with some serious anti-depressants. Funnily enough, scientists believe that people taking anti-depressants might be jeopardizing their ability to fall in love – and anti-depressants may mitigate the pain felt when one's heart is broken.

Stage 3: Attachment

This is the "you had me at hello" stage, the happy-endings stage, the Golden Anniversary stage, the grandma & grandpa together for 40 years that's heartwarming but with the advent of viagra a little disturbing stage. It's governed by two hormones – oxytocin and vasopressin. Oxytocin, a chemical related to pair-bonding, is released during orgasm by both the male and the female -- which explains why it is extremely difficult to have sex without intimacy. If some chick ever wanted more from you than you were willing to give, blame that damn oxytocin. Scientists need to get on this; if we can come up with a chemical block for oxytocin – some pill that you can take that will prevent its release during sex – then bazillions of hornballs everywhere can fuck to their hearts' content without having to worry about whether their partner is secretly picking out china patterns.

The bottom line? We become addicted to love – or rather, addicted to the chemical response that the sight/presence/whatever of our beloved induces in us…and if love is an addiction, it follows logically that there must be a cure. Rats and other seriously promiscuous animals don't have the same arrangement of receptors in their brains for vasopressin and oxytocin as we do, which means that while they feel euphoria during sex, they don't have the ability to associate that euphoria with a particular partner. Unlike us. So one would think that if we could alter this series of receptors our brains, we could wipe out sexual jealousy, attachment and most importantly broken hearts in one fell swoop – think of how awesome it would be. We could ensure the survival of our species without having to endure the pain of a broken heart or a disastrous relationship. So here's to hoping that Behavioral Geneticists are hard at work on that particular bit of genomic tinkering.

Until then, pass the Prozac.