English Version | Wings of Desire

Your stomach revolving is the opposite of turning heads, but often, when you feel your head turning, you usually also feel it in your gut. It’s that tingling sensation that means you may be falling in love, a turmoil at your core that is good and bad in equal measure. That's why we poured our heart out to find out where the phrase “butterflies in one’s belly” comes from.

Which applies not only to nervousness before a first date or in the presence of one’s love interest du jour, but is also linked to situations of greater anxiety, such as changing jobs, speaking in public, skydiving… in short, situations that cause some fear and/or enthusiasm. And this is because there are in fact winged insects in the stomach flapping their wings to warn us of these episodes out of our comfort zone... it’s what we’d say if Science weren’t here to clarify it all. Indeed, there is no butterfly party going on in one’s bowels that we forget to RSVP to. There is a scientific explanation that justifies the metaphor of butterflies, and it has to do, as expected, with the nervous system.

Although it would be very poetic to have a series of colorful moths showing proof of life in the center of one’s body every time an exciting situation or uncomfortable moment arises, what happens is much less bucolic, but nonetheless impressive: we don't realize it, but our body is in constant self-management, regulating the heartbeat and controlling the distribution of blood and nutrients to all corners of our anatomy. This process is coordinated by the Autonomous Nervous System, which controls the involuntary and unconscious activity of most of the body's organs and glands, ensuring their automatic functioning. The ANS can be divided into two strands: the rest-or-digestion mode (parasympathetic) or the fight-or-flight mode (sympathetic), constantly active and acting in opposition to each other. The heartbeat, therefore, results from the balance between these two modes - which is why, when the digestion strand (parasympathetic mode) kicks in, we feel more sluggish or sleepy, as the nervous system redirects the blood to the digestive system, encouraging the rest of your limbs to relax. On the other hand, when the fight-or-flight mode is the star, the blood is redirected to the muscles of the arms and legs, so that it can then fight or flee, leaving organs such as the stomach in the background. In other words, when this sympathetic mode - an arousal system that adapts the organism to face situations of danger, intense effort, physical and emotional stress - is activated, it also triggers the release of adrenaline and noradrenaline, which increases the heart rate, to pump blood to where it is needed most, transporting nutrients and increasing energy production. As the stomach is no longer a priority in this alert stage, the blood circulation in this area becomes less and the muscles around these organs of the digestive system decrease their action which, feeling the diminishing of blood and oxygen flow, manifest their discontent through the so-called “butterflies”, which are nothing more than this contraction due to the lack of blood flow in that area.

Romantic, right? It's not supposed to be: the symptoms are part of a primitive response to situations of danger or discomfort. As nowadays it is rare to come across natural predators, as it was with our prehistoric ancestors, instinct may not be related to a saber-toothed tiger or anything similar, but the urban jungle has shown that it has its share of emergency situations, so this nervous system response to danger is still valid. The feeling of passion and turmoil in the gut before a first date is no different - and it's not just because it's an unknown situation that it activates the nervous system. This noradrenaline, which is increased in these fight-or-flight situations, is usually released in response to stress, but also to sexual attraction. Hence the fluttering in the belly is often connoted with desire. At its core, however, the purpose is survival (as if a love interest isn't a case of survival, too) and the physiological changes triggered by the autonomous nervous system are intended to help overcome threats. In the case of a passionate crush, this focus and alertness, says an Oakland University study, helps impress your love interest. It’s also important to mention that dopamine, a substance linked to noradrenaline - which is released by the ANS in moments of alertness -, known as the well-being hormone, makes you feel happy and motivated, appearing in activities that bring us pleasure, such as a date or sexual intercourse. Both norepinephrine and dopamine can also originate in the gut, contributing to this butterfly sensation. There is a deep relationship between our brain and our bowels, and our digestive system has its very own nervous system, which is the enteric nervous system, consisting of neurons and cells that form structures called enteric ganglia connected through nerve fibers. These structures are located in the wall of the gastrointestinal tube, pancreas and gallbladder. This nervous system is linked to the brain and shares the same neurotransmitters (including dopamine) to communicate and in turn control digestion. This line of communication without intermediaries means, therefore, that emotions have a direct impact on the bowels, creating that sensation of butterflies in the belly, which, as we’ve said, is just the contraction of muscles due to the decrease in blood around these organs of the digestive system - the analogy arises because the sensation, one imagines, is similar to this flutter of flapping wings. Why butterflies? Perhaps because the association with passion needs a poetic insect. Perhaps the expression would not have so much glam if we were talking about mosquitoes or moths.

Now, if feeling butterflies in our belly can be an indicator that we are in love, does that mean that not feeling butterflies means that the passion has died? No, just that it evolved into a sense of comfort. If the autonomous nervous system triggers this fight-or-flight mode in situations of unknown, alert and danger, this must also mean that the presence of your better half has become something familiar, safe, at least in situations that have become commonplace and which do not call for caution. It went from being a saber-toothed tiger to being a fluffy cat, if we want to go back to the primitive reference. In any case, there are many situations of pleasure that can trigger the dopamine and noradrenaline that simulate this “butterflies” effect, even after crossing the border from nervousness to comfort. It may not be a first date, but the “entomological” factor is equally attainable, even if not with the same vehemence as that first encounter. The important thing to note is that a butterfly in the belly is worth more than two in flight.

Translated from the original on The Butterfly Effect issue from Vogue Portugal, published October 2022.Full story and credits on the print issue.