Love: A Journey of Emotion and Biology

Abstract

Love accompanies us from the cradle to the grave. The first and perhaps most powerful form of love we experience is a mother’s love—an intense emotional bond triggered at birth that ensures care and, ultimately, the survival of the newborn. As we grow, motherly love often gives way to romantic love between partners—a connection that may last a lifetime or be repeatedly kindled with new partners throughout our lives.

But what exactly is love? Is it something we cannot fully comprehend? A biochemical illusion? A kind of intoxication? Neuroscience seeks to understand what happens in our brains when we fall in love. Although we are far from fully grasping the neural mechanics behind love, we are beginning to decipher the changes that occur when we enter a romantic relationship and when we remain in a long-term bond.

Monogamy, for instance, is widespread in birds—over 90% of bird species involve both parents in raising offspring. In contrast, it is relatively rare in mammals, with only about 5% forming lasting monogamous bonds. Much of what we know about the neurobiology of monogamy in mammals comes from the study of voles—small, furry rodents. Interestingly, some vole species are promiscuous, while others mate for life. Research on monogamous prairie voles has revealed that two neurotransmitters—oxytocin and vasopressin—play key roles in forming long-term pair bonds. During initial mating, these chemicals modulate dopamine activity in the brain’s reward system, reinforcing a desire to remain together.

Similar mechanisms may be at work in humans. Studies suggest that oxytocin, and likely also vasopressin, contribute to human bonding, trust, and emotional connection. Serotonin levels also fluctuate when we're in love, although its precise role remains unclear. Brain imaging studies have shown activity changes across several brain regions during romantic love, but the relationship between these neural patterns and the subjective experience of love is still not fully understood.

We are gradually uncovering the neural basis of love, but a complete understanding remains elusive. And perhaps, even if we were to map every molecule and neural circuit involved, love would still retain its mystery—an emotion as complex and profound as consciousness itself.