The Biology of Longing: Why Science Says Your Soulmate is Actually an Addiction
A touch or tug you cannot feel nor see pulling your soul towards a person. The intense longing. While poets and K-drama fanatics will tell you your yearning for the other half of your being, scientists say you are essentially suffering from a chemical dependency.
For centuries we have left the definition of love to the artists. We describe it as a matter of the heart or a destiny written in the stars. But in 2005, a groundbreaking study by biological anthropologist Dr. Helen Fisher alongside neuroscientists Arthur Aron and Lucy Brown moved the conversation from the notebook of a poet to the fMRI scanner.
Their findings were startling. That invisible tug is not an emotion. It is a biological drive as powerful and primal as the need to eat, drink, or sleep.
The Brain in Love
In their study titled Romantic Love: An fMRI Study of a Neural Mechanism for Mate Choice, the researchers rounded up participants who were undeniably and madly in love. They showed them photographs of their beloveds while monitoring their brain activity.
If love were merely an emotion like happiness or sadness, the scans would have lit up the emotional centers of the brain. They did not.
Instead, the activity exploded in the Ventral Tegmental Area or VTA. This is a primitive part of the brain near the reptilian core that produces dopamine. Dopamine is the neurotransmitter responsible for pleasure, focus, and motivation. This is the same region that activates when a person takes cocaine or has an uncontrollable craving for sugar.
The Tug is Real and Involuntary
This explains the specific sensation you described as a tug you cannot feel nor see.
Because the VTA is part of the reward system rather than the cognitive system, you cannot reason your way out of it. You cannot decide to stop wanting the person any more than you can decide to stop being thirsty. The brain has marked that specific person as a survival goal.
When you are away from them, your dopamine levels drop and lead to withdrawal symptoms. You feel lethargy, anxiety, and that crushing yearning in your chest. When you see them, the dopamine floods back. You are quite literally getting your fix.
Why We Obsess
The study also shed light on why we act so irrationally when we fall in love. It explains the sleepless nights, the re-reading of text messages, and the inability to focus on work.
Fisher and her team found that this dopamine spike is often paired with a drop in serotonin. This specific chemical cocktail of high dopamine and low serotonin is strikingly similar to the brain chemistry of patients with Obsessive Compulsive Disorder. This is why the yearning feels intrusive and overwhelming because your brain is physically locking its focus onto one target.
The Evolutionary Purpose
Why would evolution burden us with such an exhausting mechanism? Why must we feel the tug and the pain?
According to Fisher, it comes down to energy conservation. Mate choice is a mechanism designed to force us to focus our courtship energy on one specific individual at a time rather than wasting time chasing every potential partner we see. That soul pull is the way nature tells us to stop looking and stick to this one to ensure the survival of our DNA.
Does knowing the science kill the romance? It should not.
If anything, the research validates what the poets have said all along. That tug is not in your head. It is woven into the very fabric of your biology. It turns out that K-drama fanatics are right about the intensity, but they were just wrong about the source. It is not magic that pulls you toward your other half. It is millions of years of evolution ensuring that when you finally find them, you physically cannot let go.
