It’s that time of year again. The science of love — and heartbreak — is in the air. That means people who’ve fallen head over heels for that special someone, or may be reeling from rejection, are asking one of the most fundamental questions of all: Why do I feel like this? The explanation is chemistry. Although science can’t explain everything about the chemistry of love, it can certainly shed light on what happens biologically when a person falls in and out of love.
Researchers who study the science of love understand that love resides not in the heart, but in the brain. Emotions are rooted in a primitive region called the limbic system, according to Healthline. The limbic system is made up of brain structures that include the amygdala, hippocampus, hypothalamus and limbic cortex. Some of these structures regulate hormones, others control memory or sensory processing. Together, they work in unison to produce emotional responses.
Years ago, a team of scientists led by Helen Fisher, a biological anthropologist at Rutgers University, embarked on a large study to get to the bottom of the chemistry of love. They found that emotional responses can be broken down into three stages: lust, attraction and attachment. At each stage, a person’s limbic system releases specific hormones and chemicals. For instance, in the early stages of lust, the hypothalamus stimulates the production of sex hormones, namely testosterone and estrogen, according to Harvard University’s Science in the News. These hormones, released in both men and women, increase sex drive and feelings of euphoria, pleasure and sexual gratification. Oxytocin, produced in the hypothalamus and secreted by the pituitary gland, rises during sex. Levels of the stress hormone cortisol also increase, prompting the human body to deal with the new, wildly disruptive feelings and circumstances, according to Harvard Medical School.
As cortisol rises, serotonin, a neurotransmitter associated with feelings of well-being and happiness, lowers. This takes place in the second stage of love: attraction. Serotonin, which is primarily found in the intestinal tract, could be responsible for the fluttery excitement in the belly that often accompanies a love interest. The decrease in serotonin could account for the loss of concentration lovers feel and the unusual obsessive-compulsive behaviors they sometimes exhibit as part of their infatuation. During attraction, the brain instigates the release of the hormone norepinephrine, which makes lovers feel giddy and energetic, and the hypothalamus releases dopamine, a chemical that alerts us that our needs are about to be met, said Loretta Graziano Breuning, Ph.D., author of “Habits of a Happy Brain.” Ultimately, brain pathways that control “reward” behavior create memories of the relationship’s early days to reinforce ongoing positive feelings, according to Science Briefss.
In the third stage, the attachment phase, lovers decide to embark on a long-term relationship. Here, oxytocin shows up again. Not only is oxytocin produced in large quantities during skin-to-skin contact and after sex, but it also floods a woman’s body during childbirth and breastfeeding. Its presence in the body helps partners feel content, calm and secure. These feelings increase the bonds between partners and also between parents and children. During the attachment stage, the hormone vasopressin works in tandem with oxytocin to reinforce those social bonds, instigate feelings of safety and influence behaviors that protect the family, a scientist from Indiana University reported in the U.S. National Library of Medicine. Both hormones are linked to actions that foster long-term, monogamous relationships. However, serotonin and cortisol levels return to normal, which may explain why passion fades as attachment grows.
The Pain of Heartbreak
Sometimes love can take a painful turn; the same hormones responsible for sparking love also play a role in the pain that accompanies a break-up. Dopamine, which is mainly responsible for the brain’s reward pathway, also creates addiction. Helen Fisher and her team at Rutgers think that, like addicts, lovers crave each other and, when the object of their addiction is taken away, a person experiences withdrawal.
In the aftermath of a breakup, it’s normal for the brain to generate thoughts of an ex at unexpected moments, according to Psychology Today. These intrusive memories can reopen wounds, reactivate pain and throw a person back into withdrawal. In one study, researchers at Columbia University found that when participants looked at photos of ex-lovers, two brain regions associated with physical pain lit up. The regions, including the insula and the anterior cingulate cortex, could be producing pains of rejection.
According to the American Heart Association, people who cannot recover from the pain of a breakup may experience stress-induced cardiomyopathy, also called broken heart syndrome. The condition can rear its ugly head not only after a breakup or divorce, but after the death of a loved one. A surge of stress hormones creates symptoms that include chest pain, irregular heartbeats and cardiogenic shock, a condition in which a weakened heart can’t pump enough blood to the body. It can be fatal if not treated immediately. Although a person with stress-induced cardiomyopathy may, at first, appear to be having a heart attack, there are several differences. First and foremost, broken heart syndromes occur suddenly after extreme emotional or physical stress. Electrocardiogram, blood and other tests show no signs of heart damage, artery blockage or unusual movement of heart ventricles.
If getting over a love interest has become particularly stressful and difficult, clinicians do have sound advice. Psychologist Guy Winch, author of “How to Fix a Broken Heart,” wrote an article for Scientific American in which he explained how the brain of a dejected lover will bombard the person with idealized snapshots, memories and thoughts of the ex and the relationship. Winch said it’s important to balance those images with reality. What of the fights? The frustrations? The compromises? The unmet needs? It’s important to remember them.
“If you are trying to get over heartbreak, make a list of the person’s faults as well as of the shortcomings of the actual relationship and keep that list on your phone. Whenever you find yourself having idealized thoughts and memories, whip out your phone and read a few reminders in order to balance your perceptions and remind yourself that your ex was not perfect and neither was the relationship,” said Winch.
Simply put, love is complicated. It can create the most wonderful feelings in the world and it can create the most painful. Although scientists are still learning how the chemicals and hormones in a person’s body interact during love, one thing’s for certain — no one can control them. But, understanding the chemistry of love can put the associated feelings, both of adoration and rejection, into perspective. What people do with those feelings is entirely up to them.