52 things I learned in 2020

Here are some of the most interesting things I learned this year:

1. The bacteria RB41 is known to exist in only three places: showerheads, dog noses, and paleolithic cave paintings. (The Great Indoors: The Surprising Science of How Buildings Shape Our Behavior, Health, and Happiness)
2. An average pair of jeans requires 6 miles of thread. In the not-too-distant past, it would have taken 110 hours to spin this much fabric. A sheet for a queen size bed requires 37 miles and would have taken 659 hours. The time cost of clothing was such that owning more than a few articles of clothing was a sign of extravagant wealth. (The Fabric of Civilization: How Textiles Made the World)
3. Cities with public libraries in the early 20th century had patenting rates 8–13% higher by the end of the century. (“Knowledge Access: The Effects of Carnegie Libraries on Innovation”)
4. Narwhals are real. (Wikipedia)
5. Tractors transformed American agriculture during the twentieth century. Within just a few decades, tractors replaced 23 million draft animals, increased cropland by 79 million acres, increased pastureland by 80 million acres, caused the disappearance of 956,000 farms, and eliminated 1.7 million farm jobs. (“Reshaping the landscape: The impact and diffusion of the tractor in American agriculture, 1910-1960.”)

   

6. In the 1860s, half of all fish caught in British waters and one-sixth of all potatoes grown in Britain were consumed in the form of fish and chips. (Cuisine and Empire)
7. At a buffet, the cheapest food and the largest serving spoons are at the beginning, because 75% of customers eat whatever is in the first tray, and 66% of all the food consumed at a buffet comes from the first three trays. Low cost items like potatoes get big spoons, and high cost items like meat get small spoons. (“The economics of all-you-can-eat buffets”)
8. People spend $7.00 on average for every hour they’re in an airport. Spending goes down 30% for every 10 minutes they wait in a security line. (“Why is airport food so expensive?””)
9. In the mid-1960s, one in twenty-seven adult women in Spain was a prostitute. (The New Spaniards)
10. Plastic bag bans come with unintended environmental consequences. When stores in California were banned from giving customers plastic bags, the amount of plastic in the environment went down 40 million pounds per year, but this was offset by an increase of 12 million pounds worth of plastic by the jump in sales of thicker and more durable garbage bags. These thicker garbage bags must be used between 9 and 26 times to offset the impact on climate change compared to the banned plastic bags. (“Plastic bag bans can backfire if consumers just use other plastics instead”)
11. Blowing out candles on a birthday cake increases the bacteria content on it by up to 1,400 percent. (The Body)
12. Raising your body temperature 3 to 4 degrees—getting a fever—to fight off microbes comes with a 20% increase in energy requirements. (The Body)
13. You’re more likely to die if it’s the surgeon’s birthday. (“Patient mortality after surgery on the surgeon’s birthday”)

    

14. Passionate kissing results in the transfer of 1 billion bacteria from one mouth to another, along with “0.7 milligrams of protein, 0.45 milligrams of salt, 0.7 micrograms of fat, and 0.2 micrograms of ‘miscellaneous organic compounds.'” (The Body)
15. In sixth century Teotihuacán (near present-day Mexico City), it was both legal and socially permissible for old women—and only old women—to get drunk in public. (Cuisine and Empire)
16. More people from dry counties die from alcohol-related traffic deaths than people from wet counties. (“Consideration of driver home county prohibition and alcohol-related vehicle crashes”) Banning smoking in bars also leads to a 4% increase in fatalities caused by drunk driving accidents, because people just go elsewhere—often more than one location—to smoke. (“The Impact of Smoking Bans in Bars and Restaurants on Alcohol Consumption, Smoking, and Alcohol-Related Externalities”)
17. A 10% increase in highway miles within a city causes a 5% increase in the weight of its exports. Within-city trade that travels on within-city highways accounts for 69% of all products and 38% of all value consumed in the city. A 1% drop in travel distance between cities increases the value of trade between them by 1.4% and total weight by 1.9%. Less than 10% of a city’s trade by weight travels farther than 1000 km. (“Roads and Trade: Evidence from the US”)
18. Corn Flakes became a commercial success only after W.K. Kellogg changed the name. Previously, the cereal had been called Elijah’s Manna. (Cuisine and Empire)
19. Interest rates have been steadily declining for 700 years, from an average rate of 15% in 1310 to near 0% in 2018. (“Eight centuries of global real interest rates, R-G, and the ‘suprasecular’ decline, 1311–2018”)

    

20. It was popular to wear a hat and cape in Spain until 1766, not only for reasons related to fashion, but because it made it possible to escape the scene of a crime without being identified. In an attempt at modernization, the king banned the hat and cape in favor of short cloaks three-cornered hats, which were popular everywhere else in Europe. Mobs took over the city in revolt, stormed the jails, and smashed Madrid’s 4,400 new oil-burning streetlamps. The king lifted the ban on hats and capes and tried a different tactic instead: from then on, the hat and cape would become the official uniform of Spain’s executioners. The hat and cape swiftly fell out of fashion. (Goya)
21. If 1/n people are infected with a disease, a gathering of .7n people is likely to include at least one infected person. For example, if there are 20,000 people infected in your area, then a gathering of 1,000 people has a 5.9% chance of having at least one infected person. (Alex Tabarrok)
22. People do not trust slow algorithms and they do not trust fast people. (“Slow response times undermine trust in algorithmic (but not human) predictions”)

    

23. People who get a trigger warning experience more anxiety for a given stimulus compared to people who do not get a trigger warning. The effect is even more pronounced for people with PTSD. (“Helping or Harming? The Effect of Trigger Warnings on Individuals With Trauma Histories”)
24. Despite the numerous benefits, being bilingual does not, in fact, make you smarter. (“Bilingualism Affords No General Cognitive Advantages”)
25. The crawling-through-air-vents-to-another-part-of-a-building trope in film first appeared in 1963 in Dr. No. (Adam Robert Thomas)
26. Swearing helps people cope with pain. People who yell the F-word can bear a 33% increase in pain tolerance compared to people who yell similar-sounding non-swear words, like “fouch”. (“Swearing as a Response to Pain: Assessing Hypoalgesic Effects of Novel ‘Swear’ Words”)
27. On Tinder, men swipe right (i.e., like) on 60% of women’s profiles, while women swipe right on only 4% of men’s profiles. (Rob Henderson) Women are also less likely to date a man whose profile picture includes a cat. (“Not the Cat’s Meow? The Impact of Posing with Cats on Female Perceptions of Male Dateability”)

    

28. You need silence to be productive. A 10-decibal increase in background noise causes productivity to drop by about 5%. (“Noise, Cognitive Function, and Worker Productivity”)
29. 62% of people who brush their teeth rinse their mouth out with water, which actually makes tooth decay more likely. The water removes much of the fluoride that would have lingered after brushing. (“Spit don’t rinse for better oral health”)
30. In India in the 1970s, young men would carry around boomboxes and play loud music in public. The trend became less popular after the government began giving away free boomboxes to anyone who got a vasectomy. (Codes of the Underworld: How Criminals Communicate)
31. Blockbuster made so much money on late fees that when they removed them in 2007 to compete with Netflix, they lost half of their profits. (SEC)

    

32. People like others a little less than 80% as much as they like themselves. For example, when given the choice between keeping $5 or giving someone else $10, people usually opt to give someone else the $10. But when the choice is between keeping $8 or giving $10, people keep the $8. (“The Evolutionary Psychology of Anger”)
33. Streetlights reduce nighttime crime by 36% and reduce “serious offending” by 4%. This is roughly the same reduction in crime you would expect from a 10% increase in policing. (“Reducing Crime Through Environmental Design”)
34. The relationship between the Road Runner and the Coyote was governed by a strict (and elegant!) set of nine rules devised by creator Chuck Jones, such as “All materials, tools, weapons, or mechanical conveniences must be obtained from the Acme Corporation” and “No outside force can harm the Coyote—only his own ineptitude or the failure of Acme products.” (Guy LeBas)

    

35. If the lawyer and the judge went to the same school, the lawyer is 4.6 times more likely to win the case. (“Quo Vadis? From the Schoolyard to the Courtroom”)
36. The more time a city spent on the frontier of the American west, the more likely the residents of that city continue to exhibit individualistic practices today. For example, they are slightly more likely to vote Republican, pay lower property taxes, and give their children more unique names. (“Frontier Culture: The Roots and Persistence of ‘Rugged Individualism’ in the United States”)

    

37. When speed dating, women pick men who are on average 25cm taller, while men pick women who are 7cm shorter. (“The height of choosiness: mutual mate choice for stature results in suboptimal pair formation for both sexes”)
38. Marrying your first cousin probably isn’t as bad as you think. Children born to first-cousin marriages have roughly the same increased risk of genetic abnormality as children born to women who are 41 years old instead of 30 years old. (“Go Ahead, Kiss Your Cousin” ) This genetic trade-off can be worth it if it enhances ties between relatives and builds community trust. (Moshe Hoffman)
39. It takes a lot of people to keep a conspiracy theory a secret. Because people break ranks at predictable rates, it’s possible to calculate the failure time of a hoax if we know how many people need to be in on the secret. For example, the failure time for a moon landing hoax is 3.68 years. (“On the Viability of Conspiratorial Beliefs”)
40. People get in car accidents roughly once every 0.5 million miles, according to the National Highway Traffic Safety Administration, compared to once every 4.34 million miles for Teslas driven on autopilot. (Tesla 2019 Q3 investor report)
41. Technically, planets don’t orbit the sun. Instead, all the mass in the solar system orbits its barycenter. Often, the barycenter happens to lie within the largest planet in a system, as it does in the Earth-Moon system. But that’s not true of the solar system: though the sun contains 99.8% of the solar system’s mass, Jupiter contains most of the other 0.2%, and it’s enough to bump the sun out of the barycenter. (James O’Donoghue)

    

42. During COVID-19, white-crowned sparrows in San Francisco changed their song to optimize for variety instead of volume, since they no longer must compete with the normal background noise of urban environments. They can now attract mates with pretty songs, not loud songs. (“How the Pandemic Transformed This Songbird’s Call”)
43. The homicide rate is lower among societies who believe in an afterlife that includes both heaven and hell. But for societies that believe in heaven only (not hell), the homicide rate is higher. Societies with a high proportion of people who believe in only heaven also have more robberies, assaults, rapes, kidnappings, thefts, and human trafficking. Apparently, the threat of eternal damnation deters such behaviors, on average, more than the promise of eternal bliss. (“Divergent Effects of Beliefs in Heaven and Hell on National Crime Rates”)
44. Sorting email into folders wastes an average of 67 hours per year. (“Am I wasting my time organizing email? A study of email refinding”)
45. In 2018, legalized marijuana in the United States led to a 27% decline in marijuana in Mexico, a decrease of 17% in gun-related homicides, and a 7% increase in overall agricultural output, compared to the years 1996–2017. (“Declining Deadly Demand? The Impact of US Marijuana Liberalization on Violence in Mexico”)
46. Canadian Mountie forts kept the peace in surrounding settlements, and the effects linger one hundred years later. As of 2014, communities located more than 100 kilometers away from former Mountie forts have 45% more homicides per capita than communities located less than 100 kilometers away. These effects are present even when people from these communities leave home: across 1,269 NHL players from 208 prairie communities, being born 10% closer to a former Mountie fort correlates with a 0.64% drop in career penalty minutes. (“The Mounties and the Origins of Peace in the Canadian Prairies”)
47. People prefer electric shocks to boredom. When people sat alone in an empty room for fifteen minutes, a quarter of women and two-thirds of men decided to shock themselves just to give themselves something to do. (“Just think: The challenges of the disengaged mind”) People who watched an 85-second video loop of a ping pong game on repeat for an hour shocked themselves an average of 22 times just to break the monotony. (“Eating and inflicting pain out of boredom”)
48. 92% of top ten Billboard songs refer to sex, with an average of 10.49 reproductive phrases per song. Among 6,000 representative songs from 2006, 90% of the sexual references are made by males at their peak years of reproductive activity. (Music: A Subversive History)
49. In work settings, people think you’re less competent when you use emojis. 😲 (“The Dark Side of a Smiley”)

    

50. In the city blocks surrounding the United Nations headquarters in New York City, most of the parking tickets issued to diplomats go to diplomats from countries with high rates of corruption. (“Corruption, Norms, and Legal Enforcement: Evidence from Diplomatic Parking Tickets”) Diplomats from countries with higher incidence of cousin marriage were far more likely to get tickets. (“The Church, intensive kinship, and global psychological variation”)
51. Trees evolved about 360 million years ago, but the fungi that decompose them didn’t evolve until about 300 million years ago—leaving a 60-million-year gap for dead plant matter to pile up, compress, dry out, and subduct. Today, we mine this ancient carbon matter as coal. (Symphony in C)
52. The wisdom of the crowd—the idea that the average opinion from an uninformed group of people is more likely to be correct than the opinion from a single expert—works even when the crowd is drunk. (“Groupdrink: The effects of alcohol and group process on vigilance errors.”)

Miscellaneous

I spent a great deal of time this year thinking about the ideas in Robert Axelrod’s The Evolution of Cooperation and Joe Henrich’s The WEIRDest People in the World. After a pre-pandemic trip to Spain, I read a stack of books on Spain’s involvement in the sixteenth century Dutch Revolt. On this, Geoffrey Parker’s The Dutch Revolt, The Military Revolution, and his biographies of Charles V and Philip II (bought based on the cover alone at a museum shop in Seville) were all excellent, though they’re not for everybody. In April, I read John M. Barry’s The Great Influenza, and ended up writing three articles for The Lynden Tribune, my hometown newspaper, on how the 1918 pandemic affected Lynden. It’s a fascinating and heartbreaking history, too much of which is repeating itself in 2020. I spent most of August thinking about diversification bias, and I spent most of October wondering if expensive wine really does taste better. (It doesn’t, though in the few weeks since I published that article, it has become the most-read and most-responded-to thing I’ve ever written by far. People have strong opinions about wine, I guess.) My favorite novel of the year was Chimamanda Adichie’s Americanah, though Emily St. John Mandel’s Station Eleven was a close second. I finally got around to reading The Count of Monte Cristo. What a book! I learned a lot from Carlos M.N. Eire’s Reformations: The Early Modern World, 1450-1650, Rachel Laudan’s Cuisine and Empire: Cooking in World History, and Ted Gioia’s Music: A Subversive History. Shaka Senghor’s Writing My Wrongs was a moving memoir. Bill Bryson’s The Body was the best science writing I read this year. The rest of the books I finished in 2020 are listed here.

Previous 52 Things I Learned: 2019, 2018