BUTTERFLIES IN THE STOMACH, ROMANCE IN THE AIR
Scientists explain why it’s so queasy to fall in love,
Lauren MacKinlay and Brad Cook married in July 2015.
The Science of Dating is an occasional series exploring the great experiment that is love and the human condition.
When Lauren MacKinlay started her master’s degree in the U.K. in 2008, she accepted an invitation from a friend to meet the other Canadian at the school.
At the Royal Central School of Speech and Drama campus pub, she was introduced to Brad Cook. She had noticed him earlier that day and couldn’t believe the coincidence, seeing the same handsome stranger twice.
She found out Cook was from Kitchener, Ont. MacKinlay, now 33, who is from Toronto, did the highway math immediately. That’s just an hour away, she reasoned. The thought “we could date,” went through her head.
She liked him immediately. Normally a composed person, MacKinlay found herself becoming “a blubbering idiot,” but worse, she had to stop herself from puking when he was around. On dates, she barely picked at her food.
“I don’t know if everyone feels this, but I felt violent butterflies. I was very nervous around him, to the point where I sometimes thought I was going to be sick.”
Thankfully, Cook found it endearing. They celebrated their second wedding anniversary this July.
That fluttery feeling is familiar to any person who has ever fallen in love, had a crush or just watched an episode of
That all-consuming physical sensation of romantic anxiety is actually a complex interaction deep within the brain that manifests in the body
“Butterflies in the stomach” is one of many ways of describing the allconsuming physical sensation of romantic anxiety.
And while it’s a universal, even charming, experience, butterflies mean that a complex interaction has been activated from deep within the brain, manifesting throughout body, including the digestive system.
“The gut is in fact a theatre in which the drama of emotion plays out,” Dr. Emeran Mayer writes in his 2016 book, The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health. The gut’s enteric nervous system is sometimes called “the second brain” because it comprises up to 100 million nerve cells.
“Any emotion or stress response that originates in the brain will send signals to the gut, which will change many gut functions,” said Mayer, a gastroenterologist, neuroscientist and professor of medicine at UCLA.
“The gut will change, like a face, associated with every emotion,” Mayer said. Emotion-related changes will also affect the gut microbes and the molecules they produce. That creates a feedback loop, by sending more information back to the brain either through the bloodstream or the vagus nerve, a neural conduit that wanders between the brain and internal organs throughout the upper body.
The vagus nerve is part of the autonomic nervous system, which has two branches. One regulates involuntary bodily functions, such as breathing, digestion and arousal. A mnemonic device for this, the parasympathetic nervous system, is “feed and breed” or “rest and digest.” The other branch is associated with the sympathetic nervous system, which is the “fight or flight” response.
Butterflies indicate “emotional arousal,” positive or negative, and can trigger a stress response, whether the brain perceives a physical threat to safety or anxious excitement on a first date.
When that happens, the hypothala- mus in the brain produces a hormone called corticotropin-releasing factor, or CRF. It’s known as the “stress master switch,” according to Mayer, and once flipped, causes a cascade of physical and mental reactions.
CRF spreads to the amygdala, which makes your hands sweat, heart race and stomach clench. CRF also signals the adrenal glands to release cortisol and adrenalin, and tells the enteric nervous system to divert energy away from digestion. The stomach slows down and may even reverse, and the intestines speed up. Blood flow is diverted to the muscles and away from the gut, meaning it’s deprived of oxygen.
Because of this complexity and uniqueness of the individual — including life history, genes, personality, circumstances and overall gut health — all this can mean an abrupt evacuation of whatever you had for lunch, pain deep in the belly or that jittery sensation.
“There’s no question that how people feel and think are highly connected with how their gut is behaving,” said Dr. Nicholas Diamant, an expert in gut-brain interaction and emeritus professor of medicine at the University of Toronto. That has implications for new research, he said, especially for when it comes to the ways digestive health and the gut’s microbiome can influence mental health and vice versa.
Psychologists have suggested the human stress response is integral to the beginning stages of a relationship and helps to form “monogamous romantic pair bonds” — also known outside of academic writing as “couples.” Social interaction, including falling in love, is enabled by experiencing, displaying and responding to emotion, which are regulated by the autonomic nervous system.
The autonomic nervous system is associated with the formation of attachment bonds through the brain’s release of oxytocin, or the “love hormone,” which has receptors on the vagus nerve and in the gut, according to a 2016 paper in the journal Social and Personality Psychology Compass. The vagus nerve also allows for emotional regulation, especially via the heart rate, which allows healthy social interaction to take place.
The stress response, especially the production of cortisol, is highly sensitive to social situations, especially ones we deem important, don’t have control over or in which we feel evaluated, said Evelyn Mercado, a postdoctoral fellow in psychology at UCLA and co-author of the study, “I love you from the bottom of my hypothalamus: The role of stress physiology in romantic pair bond formation and maintenance.”
“That characterizes relationships, especially in their first stages,” she said.
Mercado studies how our biology changes within relationships, whether romantic or familial, in terms of the production of cortisol and a salivary enzyme alpha amylase.
“When we think about stress, we think about the bad things. But what our physiology reacts to is challenges in the environment that require us to adapt. It could be a positive challenge, like meeting a person you’re interested in romantically, which requires both physical and mental resources.”
As a relationship progresses, cortisol production actually decreases when we see the object of our desire and we feel more relaxed, Mercado said. Couples said their jangled nerves were quickly soothed on their wedding day when they saw their partner at the altar. But no one is thinking about all that when they’re waiting for their date to arrive.
Tracey Hopcroft met her husband, Derek, in 2010, a time they were single but interested in other people, and she moved away to Calgary later that year. They stayed in touch on social media and, although Hopcroft never saw Derek in her future, her gut knew differently.
She returned to Toronto in 2014, heartbroken from a breakup, and agreed to drive with friends to Rochester, N.Y., where Derek, a professional athlete, was playing in a lacrosse game. Hopcroft, now 31, was so nervous she floored it the entire way.
“It was very nerve-wracking,” she said. “I had butterflies the whole time.”
They got even worse during the game. They hadn’t talked in years, but locked eyes while celebrating Derek’s team’s win.
“We didn’t even say hello. He just looked at me, came up to me and kissed me and the rest is history,” Hopcroft said. “As soon as we got together we just knew, and it was crazy fireworks.”
Derek drove her car home the next day, they moved in two weeks later, were engaged in 2015, married in 2016 and now have a 5-month-old son, Cole. While packing, a week into dating, she also had an attack of nerves. “I was sick and I was sweating and felt like I was going to barf, and I thought, ‘what the hell am I doing?’ but the day we moved in, it all went away and I was never happier.”
For MacKinlay, a digital producer for a television company, the crippling nausea is “a very distant memory.” She still gets a few butterflies sometimes, especially before seeing Cook, who works in the coaching department at the Stratford Festival, if he’s been away for a few days.
“Now the feeling mostly just comes when I’m about to go into really important work meetings,” she said.