Wednesday, 12 February 2014

Love and Other Tricks of Chemistry

Like it or not, the greeting card companies have won. Mid-February has become and will remain a celebration of love and coupling and chocolates and gift-giving. Whether you’re the type who can watch The Notebook ten times in a row and still get choked up, or an emotionless automaton you are likely to see otherwise normal people making googley eyes at each other on park benches and in restaurant windows for the rest of the week. But what is going on with these people? Are they possessed by a mystical, spiritual, connection with their one true soul-mate or is something more scientific going on?

Given that this is a science website, you won’t be surprised to hear that it’s the latter. Love, the feeling that drives us to do crazy things like build empires and spend our Saturdays at Bed Bath and Beyond, is nothing more than a trick of psychology and brain chemistry.

It all starts with infatuation. You look across a crowded room and your heart starts to beat faster as you first lay eyes on… someone who probably looks either like you or one of your parents. Yes, as gross as it may seem, research has suggested that our template for attraction is often shaped by the people who raised us. It makes sense when you think about it. Our first feelings of love are directed at our parents, so why not stick with what works? People are also attracted to versions of themselves that have been morphed into members of the opposite sex. One study found that when given a selection of pictures and told to choose the most attractive person, participants picked out a computer-morphed version of their own face over the faces of strangers nearly every time, even though they didn’t recognize the faces as their own.

So you and your doppelganger are now dating. You likely have a few things going on chemically in your body. First, your estrogen and testosterone levels have probably surged, increasing your sex drive. When you see your new partner, dopamine begins to stimulate the reward centres of your brain in much the same way as it does when you win a hand of blackjack at the casino. Norepinephrine (a cousin of adrenaline) is coursing through your brain and body just like that time when you nearly crashed your car. Only this time, you've convinced yourself it is good excitement.

You’re pumped, you’re happy, and you’re primed for some lovin’, it’s no wonder that this surge of chemicals is so addictive. Research scanning the brains of people in the early stages of love look eerily similar to those of alcoholics and drug addicts, lusting for their next hit of the good stuff. Having your brain resemble that of a problem gambler is the least of your worries, though; you are also very likely experiencing low serotonin levels comparable to those of people suffering from obsessive compulsive disorder. That explains why you literally cannot stop thinking about your partner (Sandori, 2001).

If you decide to give in to your sex hormones you may just exacerbate the problem. During sex your brain and the brain of your partner will release oxytocin, which leads to feelings of close attachment (Carmichael, Humbert, Dixon et al., 1987). Fortunately, if you get enough oxytocin, you will begin to transition back to a closer approximation of your normal self as you enter the stages of long-term love. If your relationship emerges from the initial euphoria and you don’t find your partner’s suddenly apparent flaws to be a deal-breaker, your body will begin to amp up production of vasopressin. Vasopressin has been linked to long-term, monogamous love and actively interferes with the dopamine and norepinephrine that make infatuation so much fun. You may not be as excited and horny, but you probably feel more relaxed.

The general sense of calmness and well-being you feel is being fed by a constant stream of endorphins. Congratulations, you are no longer a crazy person. Over time you can even begin to exit your love-den and re-enter society. If you’re really lucky, you might even find yourself in a situation where you’re only paying for half the rent on your one-bedroom apartment. This love thing isn’t so bad after all.
And that is pretty much it. Love isn’t a mysterious force of the universe that binds us together; it can be explained with a little psychology and a cocktail of neurochemicals. It makes sense when you think about it, evolution has programmed us to fall in love to ensure the species continues. If acknowledging that fact takes some of the romance out of love for you, you’re probably coming at it from the wrong angle. Rather than living in awe of love as the wondrous spiritual outcome of two people overcoming the odds of probability to come together and form a connection, maybe we should all just marvel at the complexity of the process and feel lucky that we have brains capable of experiencing it at all.  That is a fact worth sharing a box of chocolates over.


Sandroni P (October 2001). "Aphrodisiacs past and present: a historical review". Clinical Autonomic Research11 (5): 303–7. doi:10.1007/BF02332975

Carmichael MS, Humbert R, Dixen J, Palmisano G, Greenleaf W, Davidson JM (January 1987). "Plasma oxytocin increases in the human sexual response". The Journal of Clinical Endocrinology and Metabolism 64 (1): 27–31. doi:10.1210/jcem-64-1-27