Romantic love is a universal human experience. Matters of the heart have shaped the history, art and literature of every culture. But is romantic love a uniquely human emotion, or mere animal attraction?

Scientists have discovered mating behaviors in mammals are dictated by specific regions of the brain that control feelings of pleasure and reward. When mammals, whether person or prairie vole, engage in courtship behaviors, the neurons in these regions kick in to release hormones that intensify attraction and attachment, sealing the deal between reproductive partners.

For mammals that mate for life… or, at least, are monogamous for long periods of time… these brain chemicals play a primary role in mate preference, a sort of “I only have eyes for you” state that is independent of the sex drive and excludes other partners.

Scientists also discovered that as the intensity of the attraction diminishes over time… and the sweaty palms and weak knees triggered by the sight of one’s beloved wane… another area of the brain begins releasing pleasure hormones to keep the attachment strong.

Intense bonding to a specific partner appears to focus and conserve mating energy and assures a couple will remain together long enough to fulfill parental duties to their offspring.

Anthropologists believe monogamous attachments developed in the human family tree as many as three-and-a-half-million years ago, and humankind has never been more in love.

One thing seems clear, however… Whether love or animal attraction, the ties that bind are in the brain, not the heart.