BrainSex - Why We Fall In Love, is an interesting documentary about the science and natural findings as to why humans fall in love.
For centuries, love has been celebrated - and probed - mostly by poets, artists, and balladeers. But now, its mysteries are also yielding to the tools of science, including modern brain scanning machines.
A handful of young people who had just fallen madly in love volunteered to have their brains scanned to see what areas were active when they looked at a picture of their sweetheart. The brain areas that lit up were precisely those known to be rich in a powerful feel good chemical, dopamine - the substance that brain cells release in response to cocaine and nicotine.
Dopamine is the key chemical in the brain's reward system, a network of cells associated with pleasure - and addiction.
In the same lab, older volunteers who claimed to still be intensely in love after two decades of marriage participated in the same experiment. The same brain areas lit up, showing that, at least in some lucky couples, that honeymoon feeling can last.
But in these folks, other areas lit up, too - those rich in oxytocin, the cuddling chemical that helps new mothers make milk and bond with their babies, is secreted by both sexes during orgasm, and that, in animals, has been linked to monogamy and long-term attachment.
It's way too soon - and hopefully, always will be - to say that brain scientists have translated all those warm and fuzzy feelings we call romantic love into a bunch of chemicals and electrical signals in the brain.
But they do have a plausible hypothesis: that dopamine plays a big role in the excitement of love, and oxytocin is key for the calmer experience of attachment. Granted, the data are preliminary. But the findings so far are provocative.