Why Do We Fall in Love?

During sex, the brain releases the hormones oxytocin and vasopressin. All monogamous mammals have receptors for these hormones in the ventral pallidum, or pleasure center of the brain.

Oxytocin and vasopressin build mental imprints of the object or person associated with our pleasure. These hormones are also responsible for sexual fetishes. The imprints, or memory patterns, can include the sight, smell, sound, feeling or taste of the object or person.

In the case of the prairie vole, the mental imprint is based on smell. The scent of its mate triggers a shot of dopamine into the animal’s brain. Even if the voles don’t have sex, they still get a high when they’re together.

The ventral pallidum of the fickle meadow vole doesn’t have receptors for oxytocin and vasopressin. Thus, meadow voles can’t remember specific partners. They associate pleasure with the act of sex itself.

When researchers introduced hormone receptors into the ventral pallidum of meadow voles, the voles imprinted their partners and settled into long-term relationships.

The Chocolate Drug

In the first two stages of love, the chemical phenylethylamine also appears in the brain. Phenylethylamine is the “love drug” in chocolate. It helps maintain the euphoric high of falling in love. If partners break up, phenylethylamine levels plummet, causing depression and woe.

After two to five years, phenylethylamine leaves the body naturally. It’s replaced by other, more stable chemicals.

Love or Sex Addiction

Through imprinting and doses of pleasure chemicals, love creates an addiction to another person. Unsettling as it is, it’s a normal process of bonding and pairing.

Love or sex addiction is different. In sex addiction, the lover craves the dopamine/phenylethylamine high and will, often unconsciously, sabotage relationships that show signs of moving into the third, comfortable stage. The love addict is emotionally dependent on the relationship. The partner is secondary, and often suffers from the emotional needs of the addict.

In true love, the relationship will have its ups and downs, but it also grows and develops.

Final Word

Early in life, humans begin to create memory patterns and mental maps based on pleasure. We refine and add to them as we grow older. We’re attracted to certain people because they stimulate memories of pleasure.

As we fall deeper in love, we add details about our specific partner to our mental hoard of pleasure triggers. We lust for another shot of dopamine. When deprived of our fix, we’re devastated. When the object of our delight is near, we’re alive with pleasure.

Love fills the world with a rosy glow, but under the harsh fluorescent light of science, it’s just another chemical addiction.

Fortunately, true love is the only addiction with a happy ending.

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References:

Helen Fisher, “Why We Love: The Nature and Chemistry of Romantic Love”. Henry Holt and Company, New York.

John Money, “Love and Love Sickness: The Science of Sex, Gender Difference and Pair-bonding”. John Hopkins University Press.