The Chemistry of Love

Thousands of years ago, before any civilization had been established, before words were commonly understood, and before anyone wore clothes, mating among humans was quick, emotionally meaningless, and sometimes even violent. Mates were chosen (or a better word, in some cases, might be "targeted") based on a few main factors that determined whether or not they would be fertile and healthy: their eyes, their strength, their coat (hair), and, most importantly, the way they smell. Pheromones were, and continue to be, an important factor in choosing one's mate--whether we realize it or not.

Here's a practical application for this knowledge: When was the last time you seriously checked out someone of the opposite sex who smelled horrible? The last time you seriously checked out someone of the opposite sex who smelled nice? I'll just let you think about that, and let the point sink in.

Recently, experiments in New Mexico have discovered that women can be attracted to certain odors present in sweat. Yes, I'm talking about women of the human species here.

Certain genes called MHC genes affect the way a man's sweat smells. Women appear to be more responsive to men whose MHC genes are not too similar to her own. It is suspected that this is part of nature's way of ensuring diversity. Researchers conducted an experiment--in this experiment, it was found that among 48 couples that had been together for at least two years, the couples with the most similar MHC genes were less likely to be as sexually active with each other than those couples who had more varied MHC genes. Men appear to not be affected by the MHC genes of their partner, but women appear to more frequently cheat on their partners when the MHC genes of their partners are too similar to their own.

One of the most fascinating hormones in the brain that affects perception of love is the hormone oxycotin (not to be mistaken with oxycontin, people.). This is one of the more prevalent hormones in the brain when one experiences emotions associated with being in love.

A discovery by Donatella Marazziti of the University of Pisa (located in Italy) showed that some loving couples displayed the same low levels of serotonin, a neurotransmitter than can help instill feelings of ease or contentment, in the brain as individuals with obsessive-compulsive disorder. This could explain why sometimes during a breakup, one individual will end up becoming a crazy stalker and continue to pursue the other, even though they've moved on.

The chemistry of love is still a blooming field of research, and certainly an open-ended one. It is, however, looking more and more like our original understanding of love and affection is further from the truth than we initially thought.