Once a week.
Subscribe to our weekly newsletter.
Psychogenic shivers: Why we get the chills when we aren’t cold
Humans are particularly prone to shiver when a group does or thinks the same thing at the same time.
A few years ago, I proposed that the feeling of cold in one's spine, while for example watching a film or listening to music, corresponds to an event when our vital need for cognition is satisfied.
Similarly, I have shown that chills are not solely related to music or film but also to the practice of science (mainly physics and mathematics) and to the social logic of religious rituals. I believe that chills and aesthetic emotions in general can teach us something that we do not know yet. They can help us to understand what truly matters to the mind and to the society of minds.
When cold or sick, humans shiver. Shivering is a muscle tremor that produces heat which allows the body to maintain its core temperature in a changing world. Human core temperature can vary temporarily between about 28 to 42 degrees Celsius. Outside these thresholds, death occurs. Humans also shiver in the case of a fever, as heat slows down the rate of pathogen growth and improves the immune response of a living body. Goosebumps or piloerection (the bristling of hairs) can be side effects, as the muscle tremor causes hair to become erect which creates a thin layer of air, thus minimising heat loss. Strangely enough, humans also shiver independently of any such events. For instance, certain social situations seem to provoke the shivers.
Humans are particularly prone to shiver when a group does or thinks the same thing at the same time. When a crowd is sharing a common goal. When they listen to a national anthem or witness self-sacrifice. When they die for their ideas. When collective thought becomes more important than individual life. But humans also shiver from situations that are not social in nature. Some shiver when they manage to find a solution to certain mathematical problems for example, and so shivering cannot be reduced to a social mechanism.
Why does a psychological event trigger a physiological response related to the regulation of temperature? At a fundamental level, cognition requires change. If you stabilise a retina using adequate instruments, the organ ceases to transmit signals to the primary visual cortex, and one gradually becomes blind. From the standpoint of the sense organ, the same object never appears similar to itself twice. Two chairs are never exactly the same. In other words, one is constantly discovering a visual field. Everything you feel, you feel for the first time. Perception is really exploration and, if we can perceive anything at all, it is because we are constantly matching incoming sensory signals to available mental models. You rarely fail to recognise objects in your surroundings. The world is always already meaningful, and it is sometimes beautiful.
The process by which a mind adapts to its world is so effective that people constantly mistake one for the other. When a large part of thought matches a large part of world, one might consciously feel what we call aesthetic emotions. Historically, aesthetics is the science of how perception meets cognition, the science of how you know what you see. The majority of aesthetic emotions are unconscious. They occur every time you see something. When you see something important enough, you might experience these emotions consciously. This happens through bodily changes such as tears, heartbeat increase, sweat – or shivers. The strange thing with shivering is that humans seem to shiver both when they are perfectly capable of predicting the behaviour of external objects in real time, when it all fits together so well, and, surprisingly, when nothing at all can be predicted, when the situation goes out of control.
I propose that psychogenic shivers correspond to an event where the measure of the total similarity between all sensory signals and available mental models reaches a local peak value. This can be expressed mathematically in terms of the rate of change of a function of conditional similarity. In this context, any change in learning corresponds to an aesthetic emotion. When the function reaches a local maximum, its derivative tends toward zero, and learning slows down. This corresponds to a 'turning' point in your total knowledge. Ten years ago, Perlovsky predicted that such an event should involve knowledge about other minds and about the meaning of life.
We know that psychogenic shivers can be inhibited by an excitant, the opioid-antagonist naloxone. Naloxone is what you would inject in a clinical setting to a patient who is victim of an overdose; it is the antagonist of morphine. It does not come as a surprise that most of my subjects state that they relax after they experience an aesthetic shiver. Besides a clear analogy with the sexual drive, what does this tell us about the exploratory drive?
I argue that stories that provoke the shivers might bring about this relief of tension by allowing humans to overcome conflicts among fundamental parts of the mind. Such stories might help us to deal with internal contradictions, where both elements are equally resistant to change. Leon Festinger, who in 1957 invented the theory of cognitive dissonance, named this a dissonance of maximum amplitude. The mind creates stories to overcome its own contradictions. Anthropologists call this a myth, and we know from a wealth of work in anthropology that rituals are likely to provoke shivers down the spine.
We give two examples for such fundamental conflicts; one is biological and the other cultural. The biological conflict derives from the fact that, while we survive as a species by sharing goals, we might never access the goal of other minds directly. We thus shiver in cases of seemingly total communication – theoretical synchrony. Another example derives from the fundamental discordance between the altruistic nature of the human animal on the one hand, and the logic of the currently dominant social system on the other. These hypotheses would explain why you might shiver in the course of a film when empathy becomes a necessary condition to reduce narrative tension to its minimum. When the bad guy ends up saving the good guy.
There are three plausible explanations for the fundamental relation between cognition and temperature. One is physiological, the other is physical, and the third is biological. The physiological explanation simply consists of describing psychogenic shivers as a case of fever. The relation between emotion and temperature is in fact very ancient, and even reptiles display evidence of stress-induced hyperthermia.
The physical explanation relates the dissipation of heat at the shiver to the processing of information in the brain. In 1961 the physicist Rolf Landauer at IBM proposed the principle that any erasure of information should be accompanied by the dissipation of heat. This was verified experimentally a few years ago in Lyon. If this hypothesis is not entirely false, then we should eventually be able to predict the amount of heat produced, given accurate knowledge of the information process. Until then, I do not see any good reason to quantify the shiver.
Finally, the biological explanation relates the origins of human thought to the tremendous changes in temperature at its birth. It might be that we can observe this relation between the mechanisms that regulate cognition and the mechanisms that regulate temperature because of the particular context in which thought saw the light of day. In other words, a shiver might have very well accompanied the first human idea. Since then, every time we grasp something important, perhaps we repeat the gesture.
This article was originally published at Aeon and has been republished under Creative Commons.
- COVID-19 or anxiety? Here's how to tell the difference - Big Think ›
- Is This the Scariest Painting Ever? - Big Think ›
- Average human body temperature mysteriously declined, finds study - Big Think ›
What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
A new study finds surprising evidence of the self-evolution of urban foxes.
- A study from the University of Glasgow finds urban foxes evolved differently compared to rural foxes.
- The skulls of the urban foxes are adapted to scavenging for food rather than hunting it.
- The evolutionary changes correspond to Charles Darwin's "domestication syndrome."
How much can living in the city change you? If you were an urban fox, you could be evolving yourself to a whole new stage and becoming more like a dog, according to a fascinating new study.
Researchers compared skulls from rural foxes around London with foxes who lived inside the city and found important variations. Rural foxes showed adaptation for speed and hunting after quick, small prey, while urban fox skulls exhibited changes that made it easier for them to scavenge, looking through human refuse for food, rather than chasing it. Their snouts were shorter and stronger, making it easier to open packages and chew up leftovers. They also have smaller brains, not meant for hunting but for interacting with stationary food sources, reports Science magazine.
Interestingly, there was much similarity found between the male and female skulls of the urban foxes.
The observed changes correspond to what Charles Darwin called the "domestication syndrome," comprised of traits that go along with an animal's transition from being wild, to tamed, to domesticated.
The study was led by Kevin Parsons, an evolutionary biologist at the University of Glasgow.
"What's really fascinating here is that the foxes are doing this to themselves," Parsons told the BBC. "This is the result of foxes that have decided to live near people, showing these traits that make them look more like domesticated animals."
The researchers are not suggesting you should go out and get a fox as a house-pet just yet. But they are seeing the evolutionary process taking place that's moving the urban foxes along the path towards becoming more like dogs and cats, explained the study's co-author Dr. Andrew Kitchener from National Museums Scotland.
A fox beneath a tree in Greenwich park, south east London on May 14, 2020.
Photo by Glyn KIRK / AFP
"Some of the basic environmental aspects that may have occurred during the initial phases of domestication for our current pets, like dogs and cats, were probably similar to the conditions in which our urban foxes and other urban animals are living today," said Kitchener. "So, adapting to life around humans actually primes some animals for domestication."
The specimen came from the National Museum Scotland's collection of around 1,500 fox skulls.
You can read the study in the Proceedings of the Royal Society B.
A fox at the LV County Championship, Division two match between Surrey and Derbyshire at The Brit Oval on April 9, 2010 in London, England.
Photo by Clive Rose/Getty Images
Is Bitcoin akin to 'digital gold'?
- In October, PayPal announced that it would begin allowing users to buy, sell, and hold cryptocurrencies.
- Other major fintech companies—Square, Fidelity, SoFi—have also recently begun investing heavily in cryptocurrencies.
- While prices are volatile, many investors believe cryptocurrencies are a relatively safe bet because blockchain technology will prove itself over the long term.
Presentation slide from Sanja Kon's presentation on the evolution of money at 2020 Web Summit
Credit: Sanja Kon<p>The move came shortly after the payments company Square invested $50 million into Bitcoin, and after Fidelity announced that it was opening a Bitcoin fund into which qualified purchasers could invest <a href="https://www.bloomberg.com/news/articles/2020-08-26/fidelity-launches-inaugural-bitcoin-fund-for-wealthy-investors" target="_blank">(minimum investment: $100,000)</a>. Together, this institutional backing might have something to do with Bitcoin's recent surge back to near its 2017 price peak of $19,783. (Bitcoin is listed at 19,384.30 as of Dec. 3.)<br></p>
Presentation slide from Sanja Kon's presentation on the evolution of money at 2020 Web Summit
Credit: Sanja Kon<p>But more importantly, it suggests cryptocurrencies might soon have the opportunity to prove themselves in real-world use cases. After all, skeptics have long doubted the ability of cryptocurrencies to go mainstream as a form of everyday payment. But people seem increasingly comfortable with digital payment systems.</p><p style="margin-left: 20px;">"The entire world is going to come into digital first," Schulman said at Web Summit, adding that PayPal's services already go hand-in-hand with cryptocurrencies. "As we thought about it, digital wallets are a natural complement to digital currencies. We've got over 360 million digital wallets and we need to embrace cryptocurrencies."</p><p>Sanja Kon, vice president of global partnerships at the cryptocurrency payments processor company UTRUST, also spoke at Web Summit about the increasing adoption of digital payments:</p><p style="margin-left: 20px;">"Physical cash is becoming more and more obsolete. And the next step in the evolution is digital currency."</p><p>Kon noted some of the inherent advantages of cryptocurrencies, namely ownership. </p><p style="margin-left: 20px;">"For many people, this is really the main benefit of cryptocurrency: Users owning cryptocurrencies are able to control how they spend their money without dealing with any intermediary authority like a bank or a government, for example," Kon said, adding that there are no bank fees associated with cryptocurrencies, and that international transaction fees are significantly lower than wire transfers of fiat currency.</p><p>Kon said cryptocurrencies have unique growth opportunities in areas where people aren't integrated into modern banking systems:</p><p style="margin-left: 20px;">"With cryptocurrencies and blockchain, with the use of just a smartphone and access to internet, Bitcoin and cryptocurrencies can be available to populations of people and users without access to the traditional banking system."</p>
Bitcoin as 'digital gold'<p>Still, it could take years for people to start using cryptocurrencies for everyday purchases on a large scale. Despite this, many cryptocurrency advocates see digital currencies, particularly Bitcoin, as a way to store value—digital gold, essentially.</p><p style="margin-left: 20px;">"I don't think Bitcoin is going to be used as a transactional currency anytime in the next five years," billionaire investor Mike Novogratz recently told <a href="https://www.bloomberg.com/news/articles/2020-10-23/novogratz-says-bitcoin-is-digital-gold-not-a-currency-for-now?srnd=markets-vp" target="_blank">Bloomberg</a>. "Bitcoin is being used as a store of value. [...] "Bitcoin as a gold, as digital gold, is just going to keep going higher. More and more people are going to want it as some portion of their portfolio."</p><p>There are obvious parallels between gold and Bitcoin: Both are mined, do not degrade over time, are finite in supply, and aren't directly tied to the value of fiat currency, making them <a href="https://www.reuters.com/article/us-gold-inflation/gold-as-an-inflation-hedge-well-sort-of-idUSKCN1GD516" target="_blank" rel="noopener noreferrer">relatively invulnerable to inflation</a>. The obvious objection is that the price of Bitcoin, and cryptocurrencies in general, is far more volatile than gold.</p><p>But for investors who believe the inherent value of cryptocurrency technology will prove itself over the long term, these price fluctuations are just bumps on the long road to the future of currency. </p><p style="margin-left: 20px;">"It's no longer a debate if crypto is a thing, if Bitcoin is an asset, if the blockchain is going to be part of the financial infrastructure," Novogratz said. "It's not if, it's when, and so every single company has to have a plan now."</p>
Singapore has approved the sale of a lab-grown meat product in an effort to secure its food supplies against disease and climate change.
Approve for your dining pleasure<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="dd3f57f8baf14e654812d30a309d1f17"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/307gysA18_E?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><a href="https://www.ju.st/en-us" target="_blank" rel="noopener noreferrer">Eat Just</a>, a company that produces animal-alternative food products, announced the news earlier this week. In what the company is calling a world first, Singapore has given it permission for a small-scale commercial launch of their GOOD Meat brand product line. For the initial run, the cultured chicken meat will be sold as an ingredient in "chicken bites."</p><p>"Singapore has long been a leader in innovation of all kinds, from information technology to biologics to now leading the world in building a healthier, safer food system. I'm sure that our regulatory approval for cultured meat will be the first of many in Singapore and in countries around the globe," Josh Tetrick, co-founder and CEO of Eat Just, <a href="https://www.businesswire.com/news/home/20201201006251/en/Eat-Just-Granted-World%E2%80%99s-First-Regulatory-Approval-for-Cultured-Meat" target="_blank" rel="noopener noreferrer">said in a release</a>.</p><p>According to the release, Eat Just underwent an extensive safety review by the Singapore Food Agency. It provided officials "details on the purity, identity and stability of chicken cells during the manufacturing process, as well as a detailed description of the manufacturing process which demonstrated that harvested cultured chicken met quality controls and a rigorous food safety monitoring system." It also demonstrated the consistency of its production by running more than 20 cycles in its 1,200-liter bioreactors.</p><p>While Eat Just did not offer details on its propriety process, it likely follows <a href="https://www.newscientist.com/article/mg24032080-400-accelerating-the-cultured-meat-revolution/" target="_blank" rel="noopener noreferrer">one similar to other lab-grown meats</a>. It starts with muscle cell samples drawn from a living animal. Technicians then isolate stem cells from the sample and culture them <em>in vitro</em>. These cultured stem cells are then placed in a bioreactor, essentially a fermenter for fleshy cells. The bioreactor contains scaffolding materials to keep the growing tissue from falling apart as well as a growth material—the sugars, salts, and other nutrients the tissue needs to grow. As the cells grow, they begin to differentiate into the muscle, fat, and other cells of meat tissue. Once grown, the tissues are formed into a meat product to be shipped to restaurants and supermarkets.</p>
An abattoir abatement?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg2Mjg5OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyODg1NDI3N30.AYmFJfWQbPjK-o1IatyFHL-OLjcfXBMmQKYyvz4oT3s/img.jpg?width=980" id="8a82d" class="rm-shortcode" data-rm-shortcode-id="93f824fe4c6f397ab2b65e4665847e71" data-rm-shortcode-name="rebelmouse-image" />
A graph showing the number of animals slaughtered in the United States per year from 1961–2018.
Credit: Our World in Data<p>Singapore's approval is an important step in support for clean meats—so-called because they don't require animal slaughter and would likely leave a reduced carbon footprint—but hurdles remain before widespread adoption is possible.</p><p>The most glaring is the price. The first lab-grown hamburger was eaten in London in 2013. <a href="https://www.bbc.com/news/science-environment-23576143" target="_blank" rel="noopener noreferrer">It cost roughly $330,000</a>. As with any new technology, investment, iteration, and improved manufacturing will see the price drop substantially and quickly. For comparison, Eat Just's chicken will be priced equivalent to premium chicken.</p><p>Other hurdles include up-scaling production, <a href="https://www.nature.com/articles/d41586-019-00373-w" target="_blank" rel="noopener noreferrer">the need for further research</a>, and developing techniques to reliably produce in-demand meats such as fish and beef. Finally, not all countries may be as receptive as Singapore. Countries with large, entrenched meat industries may protect this legacy industry through a protracted and difficult regulatory process. Though, the meat industry itself is investing in lab-grown meat. Tyson Foods, for example, has <a href="https://euromeatnews.com/Article-Tyson-Foods-announces-investment-in-clean-meat/697" target="_blank" rel="noopener noreferrer">invested in the food-tech startup Memphis Meats</a>, the company that debuted the world's first beef meatball.</p><p>"I would imagine what will happen is the U.S., Western Europe and others will see what Singapore has been able to do, the rigours of the framework that they put together. And I would imagine that they will try to use it as a template to put their own framework together," <a href="https://www.reuters.com/article/us-eat-just-singapore/singapore-approves-sale-of-lab-grown-meat-in-world-first-idUSKBN28C06Z" target="_blank" rel="noopener noreferrer">Tetrick told Reuter's during an interview</a>.</p><p>Regardless of the challenges, the demand for meat substitutes is present and growing. In 2020, plant-based substitutes like Beyond Meat and Impossible foods <a href="https://bigthink.com/coronavirus/plant-based-meat" target="_self">gained a significant foothold in supermarkets</a> as meat-packing factories became coronavirus hotspots. The looming threat of climate change has also turned people away from meat as animal products. Livestock production is environmentally taxing and leaves <a href="http://css.umich.edu/factsheets/carbon-footprint-factsheet" target="_blank" rel="noopener noreferrer">a much larger carbon footprint</a> than grain and vegetable production. </p><p>Then there's the moral concern of animal cruelty. In 2018 alone, 302 million cows, 656 million turkeys, 1.48 billion pigs, and a gob-smacking 68 billion chickens were <a href="https://ourworldindata.org/grapher/animals-slaughtered-for-meat" target="_blank" rel="noopener noreferrer">slaughtered for meat worldwide</a>. And those figures do not include chickens killed in dairy or egg production.</p><p>If brought to scale and widely available, clean meats could become serious competitors to traditional meat. <a href="https://bigthink.com/technology-innovation/meat-alternatives" target="_self">One report has even predicted</a> that 60 percent of the meat people eat by 2040 won't come from slaughtered animals. It could be just the thing for people looking for a meat substitute but who find tofurkey as distasteful as, well tofurkey.</p>