Science tries to reveal the mysteries of chills

It usually happens when a song or a movie strikes a chord with us, or when we’re remembering powerful events — be they heroic or altruistic — that have deep roots in our memory. We also get chills when we experience intense personal moments, such as a warm hug, an overwhelming feeling of belonging, or a powerful connection with other beings, or with the immensity of nature. Sometimes, the stimulus that provokes chills can seem melancholic. It may even contain a certain amount of helplessness. But the physiological response is as pleasant as it is elusive when trying to explain it.

Its external manifestation is hair standing on end (piloerection, commonly known as goosebumps) and a slight shivering. More subjectively, the “aesthetic chill” — how the literature refers to it, to differentiate it from its negative side, which emerges in a state of terror, or the purely physical chill, which appears when we have a fever — offers endless descriptions. One of hundreds possible is that of an icy flash, which crosses our back and spreads through the rest of our body, giving us a tingling sensation. Some people compare it to a mini-orgasm, or to a mystical and fleeting ecstasy. Poetry has been trying to capture its essence for millennia. And science has spent decades trying to unravel its mystery.

Félix Schoeller, from the Institute for Advanced Consciousness Studies, based Santa Monica, California, has focused his work on answering the questions raised by these tsunamis of unleashed emotionality: What are the most common triggers of chills? Can the pleasant sensations help people with mental health problems?

He and his colleagues have created ChillsDB: a database of music, movies and speeches that are especially likely to give us goosebumps. The repository was examined in an article in the scientific journal Nature in 2022. Thousands of Californians have been exposed to its contents. In a video call with EL PAÍS, Schoeller explains that machine learning models help refine the analysis: “We want to produce as many chills as possible. And we increasingly know how to do it, depending on the personality, demographic characteristics and specific status of the individual [being tested].”

It’s still not known with certainty why this outbreak of comforting coldness occurs. In a fertile terrain for speculation, several hypotheses have attempted to reveal its evolutionary roots. The late neuroscientist Jaak Panksepp linked musical chills to social loss. In a much-cited 1995 study, Panksepp showed that sad tunes shake us up inside much more than happy ones. He also suggested a possible association between hairs standing up on our skin with the ability to evoke loneliness. This theory, as explained by Tuomas Eerola, professor of musical cognition at the Durham University (United Kingdom), “connects [aesthetic] chills with thermoregulatory modulation, since [even imagined] isolation can make us feel very cold.”

Schoeller notes that, “originally, [chills were] associated with tremors, muscle movements that produce heat and keep the body temperature stable.” However, he adds that, for him, “the important thing is that chills occur regardless of thermal changes in our body.” And they happen for countless reasons, from listening to Mozart, to participating in a ritual, or solving an equation. “Many people tell me that they can be generated through thought,” he points out.

The sequence that’s repeated in his empirical observations seems clear. “A stimulus causes a response that, while it comes from the brain, manifests in the body and, in turn, the brain interprets it as something important. Then, we perceive everything else differently. It’s like a loop that involves the brain, body and surrounding reality.”

At a neurobiological level, it’s also known that, behind the hairs that stand up (at least when listening to music), there’s a hidden release of dopamine, the so-called “pleasure hormone.” In another landmark study, published in 2001 by Anne Blood and Robert Zatorre, it was found for the first time that, during chills, the famous reward system that traps drug addicts is set in motion. And something else, Schoeller emphasizes, appears in its ephemeral duration: “There’s a curious phenomenon of deactivation of the amygdala (the part of the brain that prepares us for fight or flight when faced with a supposed threat)... just the opposite of what happens during the fear response, in which it’s activated.” In some way, the aesthetic chill informs us about the absence of danger: it tells us that everything is going well.

The only way out

Authors such as Mathias Benedek and Christian Kaernbach have linked chills to a kind of conciliation between opposites. It seems common for the fusion of sorrow and joy, or pain and love, to light its spark. Professor Eerola refers to a video in which high school students honor their deceased teacher with a haka, that high-voltage Maori warrior dance famous for being the distinctive ritual performed by New Zealand’s national rugby team. “There’s a resolved conflict in the [performance], in which aggression cannot be separated from sadness… this is something that we cannot easily understand. The mixture [between the two sensations] is the only way out,” he maintains. Schoeller confirms that mixed states of emotions, “such as witnessing an act of great solidarity amidst tragedy,” tend to chill us.

Broadening the view, both authors allude to the expression of “being moved.” Schoeller highlights that this is “used in the literature of affective neuroscience to categorize various states [of being],” such as chills, the crying that comes from joy, or bursts of vague optimism, sometimes accompanied by a feeling of warmth in the chest.

The first cousin of “being moved” would be the notion of kama muta, a somewhat elusive Sanskrit term that, in its new scientific definition, encompasses emotions of comforting and expansive love, with a social dimension. A group of psychologists and anthropologists from the universities of Oslo and California created the Kama Muta Lab in 2017 and have been dedicated to examining this emotional typology since then. In a 2020 study published in the journal Psychophysiology, these types of experiences were found to increase levels of piloerection (goosebumps) and decrease the heart rate. With its symbiosis of calm and exuberant bliss, a kama muta moment seems to be the honey that’s dribbled over the chill.

Another doubt that scientists are trying to resolve refers to the enormous variability of experience. Some people get chills every now and then, while others don’t know what it feels like. In 2022, researcher Giacomo Bignardi and his colleagues demonstrated, thanks to an analysis of identical and non-identical twins that appeared in Nature, that genetics partly determines the propensity to shudder when we read poetry or see art. The similarities in the response were twice as high between identical twins compared to non-identical twins.

In the same study, it was also observed that women are more likely to delight in the experience than men, although the difference isn’t substantial. And, as we grow older, we’re moved more frequently by verses or paintings. “If emotional peaks (a category in which chills are usually included) reflect something about ourselves, it makes sense that, the longer we’ve lived, the more often those occur,” Bignardi tells EL PAÍS. He conducts his research at the Max Planck School of Cognition, in Leipzig, Germany. Paradoxically, he continues, it turns out that, when one gets chills while listening to music, the opposite is detected: “There are no conclusive results, but it seems that they appear more often among young people.”

Eerola, a musical expert, mentions the obstacles that arise while tracking the incidence of chills and looking at the sensation in detail. One obvious issue has to do with the site of observation. “I wish we were able to study it in real contexts, at concerts or with people relaxing at home with a couple of glasses of wine,” he sighs. Above all, Eerola continues, getting chills is by no means a “frequent or automatic reaction, except in people very open to an experience.”

Despite these difficulties, Schoeller hasn’t given up his efforts to better understand the ins and outs of chills. He has even begun to sense a common denominator among certain individuals who experience this emotional peak: “The capacity for absorption, to be focused on a task and immerse oneself in it.” His research has revealed that this electrical and sparkling invasion also provokes — even if only for a few moments — a very liberating feeling of self-transcendence.

In another study, Schoeller also found that getting chills can help “mitigate maladaptive cognition” in patients with depression, since they “foster an emotional breakthrough that calls into question long-held beliefs about ourselves.” For example, the notion that we’re useless, or that we’re doomed to failure. With accurate and prolonged exposure to proven effective stimuli, such as those stored by ChillsDB, Schoeller thinks the benefits could be longer-lasting, thus helping to modify distorted thought patterns. Downloading sublime emotions can help us fight off persistent self-flagellation.

Translated by Avik Jain Chatlani.

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