Archive for the 'human evolution' Category

What is Teaching?

Sunday, April 6th, 2014

Russ Roberts says:

Great teaching is more than passing on information. For that you can read a book or watch a video. A great teacher provokes and takes you on a journey of understanding. That requires grappling with the material and making it your own. Usually that means applying your knowledge to a problem you haven’t see before. At least that’s often the case in economics. I think Doug Lemov said it in his EconTalk episode — you haven’t taught it until they’ve learned it and learning is more than just hearing the facts or the answer to a problem.

This was the view I heard at UC Berkeley among faculty — when they weren’t complaining about teaching.

I disagree with this. The best teachers bring out what is inside their students. They provide the right environment so what is inside each student is expressed. How to do this will be different for each student, so you have to learn about them — not just generally, you have to learn about each one. (Or at least you have to grasp their diversity and allow for it.)

Learning is natural. Every student, in my experience, wants to learn something. What makes the situation much more difficult, is the false assumption that every student wants to learn the same thing or can be cajoled into learning the same thing. One of my Berkeley students said that in high school he had had a “great teacher” of philosophy, much like the teachers that Roberts praises. He had made philosophy so interesting that my student had originally majored in it. That had been a mistake, said my student.

I believe human nature has been shaped in many ways to make our economy work. Human economies center on trading. You make X, I make Y, we trade. If everyone made X, that would be bad economics. So we have been shaped to want to go in different occupational directions — you want to be an Xer, I want to be a Yer. This is deep inside us and impossible to change. When healthy students have trouble learning, I think the underlying problem is their teacher wants them to be an Xer (like the teacher) — but they want to be something else. A great teacher finds that something else.

Even the term great teacher is misleading, because it seems to imply that being a great teacher (= every student learns a lot) is difficult. I have found it’s easy, just as swimming with the current is easy. It requires a certain psychological ingenuity to fit this way of teaching into a system that doesn’t understand it. But after I figured out how to do it, it was so much easier than teaching the traditional way. I used to try to make all my students learn the same thing. That was really tiring — like swimming against the current. After class I’d be exhausted. Now I feel fine after class.

“Why Fuss About Paleo Life?”

Wednesday, March 26th, 2014

dearime asks:

Why do people fuss so much about paleo life? The population has grown so much since that it’s easy to believe that we’ve evolved a long way from then.

Jared Diamond wrote a paper about rapid evolution on an isolated island. When modern (factory) food was introduced to the island (in the 1940s?), there was a very high rate of diabetes, presumably due to the new food. Since then, the rate of diabetes on the island has gone way down, although they still eat modern food. Diamond took this to be due to evolution (people with diabetes-resistant genes had more offspring), supporting dearime’s point of view.

After the first Ancestral Health Symposium, Melissa McEwen commented how unhealthy many of the top people looked. On the other hand, Tucker Max commented how healthy the attendees looked in general. I agree with both observations. A paradox.

When I was an assistant professor, and wanted to sleep better, I believed wondering about paleo life was unhelpful because (a) we knew so little about it and (b) it must have differed in thousands of ways from modern life. Should I spend an hour trying to find out about paleo life and/or what paleo gurus recommend for bad sleep? Or should I spend an hour trying to find out how ordinary people have improved their sleep? My answer was the latter. I ignored paleo life.

Looking into how ordinary people improved their sleep did help. I eventually reached a non-trivial conclusion: Eating breakfast made my sleep worse. No paleo guru had said that — I had been right to ignore them. Yet it made evolutionary sense. Cavemen did not eat breakfast, I was pretty sure. (No refrigerators.) After that I paid more attention to what evolutionary thinking would suggest. This led to several discoveries: the effect of faces in the morning on mood, the effect of standing on sleep, and the Shangri-La Diet. It is incredibly hard to discover big new experimental effects (such as the effect of morning faces), especially in fields you know little about (my specialty in psychology was animal learning, not mood, sleep or weight control). I was impressed.

The effect of bedtime honey (more generally sweets in the evening) on sleep emphasizes the paradox or puzzle or whatever you call it. I found out about the honey effect by paying attention to what works. No paleo involved. Stuart King told me it improved his sleep. Here are three reasons to look at ordinary experience and avoid paleo theorists: 1. It turned out to help. 2. It’s a huge effect and very easy. 3. Paleo theorists have said the opposite: avoid carbs, avoid sugar. If you followed their advice, you would do the opposite of what helped Stuart and me. On the other hand, I increased my belief in the effect because it made evolutionary sense: 1. It makes sense of why we like sweets. 2. It makes sense of why our liking for sweets goes down when we are hungry (surely due to an evolved mechanism). 3. It makes sense of why we eat sweets more in the evening (presumably due to an evolved mechanism that makes sweets taste better in the evening).

The short answer to dearime’s question is that, in my experience, it is incredibly hard to learn anything about health. There are so many possibilities and evolutionary thinking helps choose among them — decide which to take the trouble to test.

Nick Szabo is Satoshi Nakamoto, the Inventor of Bitcoin

Tuesday, March 11th, 2014

There were many funny things about Leah Goodman’s claim in Newsweek that a California engineer invented bitcoin. One was her observation that he put two spaces after a period — just like the inventor of bitcoin. Another was her observation that his relatives said he was “brilliant”, without giving any examples. His brilliance had remained perfectly hidden – until now. A third was her conclusion that he was obsessed with secrecy and distrusted government – just like the inventor of bitcoin (according to her). Felix Salmon was quite wrong when he said there are some very strange coincidences and the pieces of her argument “fit elegantly together”. Actually, her argument is worthless from top to bottom. Salmon was right, however, when he said that the engineer’s English shows he couldn’t possibly have invented bitcoin. As Salmon says, Goodman ignored this itty-bitty problem.

Who is the inventor of bitcoin? I’m sure it’s Nick Szabo, a former law professor at George Washington University. This idea first surfaced a few months ago in an anonymous blog post based on textual analysis. Szabo used certain phrases in the original bitcoin description far more than a bunch of other possible candidates. That is real evidence. The hypothesis that Szabo is the inventor passes several other tests as well: (more…)

Elegant Variation, Fashion and Employee Free Time: What Do They Have in Common?

Sunday, February 16th, 2014

I am learning Chinese by studying a Chinese version of The Three Little Pigs. The story contains a phrase that irritated me: “Three’s home” (in Chinese). Although I did know the Chinese for “home”, the rest of the story used the term “Three’s brick house” (in Chinese). Why couldn’t they stick with one name for it? I thought.

I knew the answer: In language, we like to use different words for the same thing. A famous archeological decipherment puzzle was solved when someone realized the stone cutter had used different words for the same thing. A little repetition is okay but extreme repetition is not. Thus the term elegant variation. Using different words for the same thing is not just confusing, it makes the language harder to learn (because it is larger), with no obvious improvement in breadth or speed of communication.

Why do we do this? Why do we dislike certain sorts of repetition, even though language is built on repetition? I think the answer is that this is built into us to help the language to expand and grow. The variation seems useless but it isn’t because (a) there is a new word and (b) the new word can shift in meaning. The old word can continue to mean what it meant.

Fashion has a similar function. Our shifting preferences in art and decoration force artists to keep inventing. They cannot merely do the same thing over and over and over. Fashion obviously increases innovation.

In her brilliant book The Good Jobs Strategy, Zeynep Ton, an MIT business professor, says that retailers should “operate with slack” — meaning hire more employees than necessary. The effect is to give employees some free time. Why should this be? Because when you give employees free time you give them to think. Giving them time to think gives them time to think of improvements.

Language (elegant variation) and material science (fashion) might be more central to human life than well-run stores (slack) but in each case there are real problems to solve — and they are solved, in part, by adding seemingly-useless elements to the system. The new elements help the system improve.

Why Fashion Evolved

Saturday, November 9th, 2013

My theory of human evolution says that fashion (changing preferences for well-made goods) evolved so that artisans — the innovators of long ago — would not do the same thing over and over. In an excellent interview, music producer T Bone Burnett says something similar:

I don’t believe in crowdsourcing [for artists] because you’ll end up doing the same thing over and over again. People tend to want artists to do the same thing, and it is incumbent upon artists to do something that the audience doesn’t want — yet.

I’ve had a hard time finding interesting work by economists on the causes of innovation. It isn’t just institutional structures (“extractive” versus “inclusive”), as Acemoglu and Robinson say in Why Nations Fail. (Better title: One Reason Nations Fail.) An exception is Nathan Rosenberg, an emeritus professor at Stanford, for example this paper about aircraft design.




Mo Ibrahim: How I Became a Teacher

Tuesday, October 22nd, 2013

I met Mo Ibrahim, a high school teacher in New York, because of his Behind the Approval Matrix  blog, which I admired. I interviewed him about his I Got Uggs! blog. Recently he has become interested in finding out if my ideas about teaching can help him teach better. This is the first in a series of posts by him about that.

I went to college at Chicago State University, a commuter school in Chicago. I started in the late 1980s. I considered a career as a teacher when I was there, but changed my mind after I visited the education department and learned about the student teaching requirement, which seemed like a drag. Later I visited the premed office. Mostly I studied biology and graduated with a degree in Independent Studies. By graduation, I had been accepted at University of Illinois School of Medicine, in Chicago.

I started there in 1995. The summer before I enrolled, I had been verbally promised a whopping three scholarships. One was from my State Representative, the other two from a non-profit organization that helps African-Americans get into medical school.  I did get the scholarship from the State of Illinois, which covered my tuition. However, I never got the other scholarships, which meant that my living expenses weren’t covered. Between the time of the verbal promise and my enrollment, the organization had started a policy of only giving scholarships to students in the second and later years of medical school. Too many African-American students dropped out in the first year; the foundation reasoned it was wasting its money.

At the medical school’s financial aid office, I was informed that my only option was to take out a loan. This was something I had sworn I would never do. I’m Muslim; interest-based loans are against Islamic law. Despite being told that it was virtually impossible to be a medical student and work, I got a job during the graveyard shift at a seedy hotel on the North Side. I avoided drinking coffee to stay awake because I didn’t want to go to the bathroom and compete with the rats for a stall. Without coffee, I fell asleep. I was only there a week. A tenant who owed the hotel over $1,000 moved out while I was asleep. I was immediately fired. Three months later, I withdrew from medical school. I couldn’t afford it.

My first real job after medical school was in the medical records office at St. Francis Hospital. A co-worker was taking a computer repair class at a community center and suggested that I join him. I didn’t take the class, but I purchased a used computer, some computer repair books, and studied for the A+ Certified Computer Repair Technician exam. I passed the exam on the first attempt and got a job making five times what I was making at the hospital. I did computer repair and network engineering for five years. Unfortunately, the work seemed to be drying up. I started at $100/hour but after five years was making $9/hour. Toward the end of the five years, my wife and I took a vacation in New York City. In the subway, I noticed an advertisement for the New York City Teaching Fellows (NYCTF) Program. I liked the idea of being a teacher because of the job stability and the idea of giving back to the minority community. NYCTF automatically puts you in an “underprivileged” school. The deadline for applying to the program was quickly approaching and I filled in the online application as soon as I returned to Chicago.

I was invited back to New York for an interview. After I taught a sample lesson and did group and one-on-one interviews, I was accepted into the 2004 NYCTF program. That summer I enrolled in a Master’s degree program in in Education at the City College of New York. I also got a job teaching at an underprivileged high school near Columbus Circle. Ten years later, I am still trying to determine the best way to teach my students.

My Theory of Human Evolution: Obsessive-Compulsive Disorder

Friday, October 18th, 2013

From Entertainment Weekly:

EW: Are you religious?

Jodie Foster: No. I’m an atheist. But I absolutely love religions and the rituals.

Perhaps everyone enjoys rituals. (Even scientists.) It’s a curious enjoyment because rituals are arbitrary and without useful result. No other species has rituals. One sign of the pleasure we derive from rituals is obsessive-compulsive disorder (OCD). OCD takes many forms; one is excessive dependence on rituals, such as a need to do certain things, such as counting, tapping, or aligning, so often that it seriously interferes with being productive. The BBC program Am I Normal? did an excellent episode on OCD (no longer available). If you think of OCD (some forms) as addiction to rituals, the capacity of rituals to provide pleasure — or at least reduce anxiety — is clear.

Why do we enjoy rituals? I’ve already written about Christmas. Rituals and ceremonies, like Christmas and other gift-giving holidays, are a growth medium for fine craftsmanship. They encourage desire for fancy things – Christmas cards, special food, music, art, the special tools used in Japanese tea ceremonies. (Maybe the word fancy was invented to describe just these things, it fits so well.) They help support the highly-skilled artists and artisans who are advancing the state of their art. You can read my whole theory of human evolution here.

Assorted Links

Monday, October 7th, 2013

Thanks to Aaron Blaisdell and Peter Lewis.

The Willat Effect With Gin

Thursday, October 3rd, 2013

The Willat Effect — named for Carl Willat, whose limoncello comparison tasting made me notice it — may happen when you experience two similar versions of one thing close together. (For example, sip one limoncello and then sip another.) The differences between them  become clearer, of course. The Willat Effect is the less obvious hedonic change: suddenly the differences matter. Suddenly one version is more pleasant, the other less pleasant.  The hedonic changes are large enough to change how I spend money (I buy the better version more, the worse version less).  I believe this effect turns people into connoisseurs.

I recently noticed the Willat Effect with gin. As part of a project to buy every type of not-too-expensive alcohol in a nearby liquor store, I bought a bottle of Bombay Sapphire London Dry Gin. I neither like nor dislike gin,  it was just something they sold I hadn’t tried.  It was medium-priced (about $20). I liked it okay.

I returned to the liquor store. This time I bought two brands of London dry gin: Tanqueray (about $20) and Greenall’s Special (about $15). At home I tasted them side by side. The Tanqueray was much better, I noticed right away. It was softer, more rounded, and had floral overtones absent from the Greenall’s. Where was the Bombay Sapphire gin on these dimensions? Did it have floral overtones? I had no idea. Now I was curious. One close comparison shifted my buying habits in two ways: (a)  I want to make more of these comparisons. I want to try every brand of gin in the liquor store to see if the cheaper brands tasted worse. (b) Apart from these comparisons,  I will never buy inferior gin again.

The Willat Effect happens only if the two things being compared are neither too similar nor too dissimilar. Perhaps differently-priced versions of London dry gin are roughly the right distance apart and are a convenient way to demonstrate the effect. It’s easy to get different versions of London dry gin.

The effect interests me because it is (a) practical (a source of enjoyment), (b) a subtle comment on intellectuals (who complain about our “consumerist” society) and economics (I look forward to an economist’s explanation of connoisseurship), and (c) it supports my theory of human evolution, which says connoisseurs came to exist because they promote technological innovation. Connoisseurs make it easier for the most skilled craftsmen — the ones most likely to innovate — to make a living.



Hobbyist Science vs. Professional Science vs. Personal Science

Friday, September 13th, 2013

In a TED talk, Paula Scher, a graphic designer, told how a hobby of painting maps turned into something like a job.

I was up in my country house, and for some reason, I began painting these very big, very involved, laborious, complicated maps . . . They would take me about six months initially, but then I started getting faster at it. Here’s the United States. Every single city of the United States is on here. . . . One of my favorites was this painting I did of Florida after the 2000 election that has the election results rolling around in the water. . . . Somebody . . . saw the paintings and recommended them to a gallery, and I had a first show about two-and-a-half years ago, and I showed these paintings that I’m showing you now. . . . They sold quickly, and became rather popular. . . . The gallery wanted me to have another show in two years, which meant that I really had to paint these paintings much faster than I had ever done them. . . . I was no longer at play. I was actually in this solemn landscape of fulfilling an expectation for a show, which is not where I started.

A hobby turned into a job. This has happened countless times — I believe all jobs started as hobbies.

One hobby that turned into a job is science. The first scientists were hobbyists — for example, Darwin and Mendel. The success of hobbyist scientists led to the creation of full-time jobs that included doing science — professors of science at universities. When science became a job, something was gained (professionals had more time per day, money, training, institutional support, collegial support, and prestige than hobbyists) and something was lost (professionals had less freedom than hobbyists). Professionals could do many things hobbyists could not, but the reverse was also true: hobbyists could do many things professionals could not. For example, they could work on a question for ten years without publishing anything (Mendel, Darwin) and entertain highly heretical ideas (Darwin). Professionals needed steady output and dared not offend, for fear of losing their job.

My personal science (personal science = using science to help yourself) is another step in this history. I combined the freedom of hobbyists with the knowledge, skills and resources of professionals. I can do whatever self-experiments I want and test whatever ideas I want. Yet I also have professional levels of training, knowledge, skill, and (to some extent) equipment provided by my job as a psychology professor, Berkeley library access, the Internet, free software, and cheap computers. To these two elements — the freedom of hobbyists, the resources of professionals — my personal science added a third element not found in hobbyist or professional science: the motivation of a person with a problem. I wanted better health. My personal science helped me get it. In the beginning, I wanted to sleep better, lose weight, have less acne, and be in a better mood. Later, I discovered new ways to improve my brain function and blood sugar. Just combining the freedom of hobbyists with the resources of professionals, personal science would probably be a big improvement. Adding better motivation suggests that personal science is even more likely to improve our lives by learning what professional scientists haven’t learned. The combination of professional science and personal science will be far more powerful (= more useful) than professional science alone.

I’ve seen this in my own life, over and over, and I predict it will eventually be true for everyone. Learning how to control one’s own health — how to sleep well, for example — is non-trivial knowledge.

Occupational Specialization as Far Back as the Bronze Age

Sunday, June 16th, 2013

Linear B is an ancient form of Greek, used around 1500 BC (the Bronze Age) in Mycenean Greece. Stuff written in Linear B gives us one of our oldest views of human life and can reveal things that other ways of looking at the past (e.g., bones, genes, tools, pottery) cannot. At the end of The Riddle of the Labyrinth (2013) by Margalit Fox, a book about how Linear B was deciphered, is a section about what the deciphered tablets turned out to say.

One thing they revealed is considerable occupational specialization. According to Fox  (pp. 273-5),

Mycenaeans plied a range of trades. Many tablets reveal the names of occupations . . . metalsmiths . . . textile work . . . tanners . . . leatherworkers . . . priests and priestesses . . . soldiers, rowers, and archers . . . swordmakers and bowmakers, chariot makers and chariot-wheel repairmen . . . goldsmiths and perfumers . . . woodcutters, carpenters, shipbuilders and net makers; fire kindlers and bath attendants; heralds, hunters, herdsmen, and beekeepers. . . . bronzesmiths.

Occupational specialization is at the center of my theory of human evolution. The decipherment of Linear B showed that it has existed as far back as we can see. Today there is an enormous amount of occupational specialization, but it also flourished when accumulated knowledge was much less.

The more you see the centrality of occupational specialization to human nature, the more you will see how modern schooling malnourishes almost everyone who undergoes it — which is almost everyone. Human nature takes people at one place and time — such as Mycenaean Greece — and pushes them to become adults who do all sorts of different things (woodcutter, herald, beekeeper . . . ). It takes people who start off the same or almost the same — same place, same food, same weather, similar genes — and creates diversity among them. Modern education tries to do the opposite: Take a diverse set of students and make them the same. One example is No Child Left Behind. Another is that in almost every college class, all students are given the same material, the same assignments, and graded on the same one-dimensional scale. We don’t need everyone to be the same; in fact, we need exactly the opposite. The more diverse we are, the sooner we will find solutions to pressing problems, because they will be attacked in many different ways.

Aquatic Ape Theory Revised

Tuesday, June 4th, 2013

I became interested in the aquatic ape theory of evolution because it pointed me in a fruitful direction — testing omega-3 fatty acids (e.g., flaxseed oil), which turned out to have easy-to-detect benefits (better brain function, better gums). That is more than I can say for alternatives to that theory, such as the savanna theory. Marc Verhaegen, a Belgian doctor, has recently proposed a new version of the aquatic ape theory. Some of his main points:

  • An extensive overview of the literature by Stephen Munro showed that virtually all known archaic Homo [= pre-Homo sapien] sites (including those in ‘savanna’) were associated with permanent water and edible shellfish.
  • Only regular diving can explain archaic Homo’s pachy-osteo-sclerosis (POS), the extreme thickness and density of cranial and postcranial bones of most erectus-like fossils. . . . POS is only seen in slow littoral divers, e.g. dugong and manatee, walrus, Kolponomos, pakicetids, Odobenocetops, and Thalassocnus spp. Marine biologists agree POS has a hydrostatic function (ballast).
  • The abundant brain-specific nutrients in aquatic foods (e.g. DHA, iodine) facilitated fast brain growth (sapiens’ poorer post-aquatic diet required a longer youth to grow the same brain size).
  • Man is the opposite of a savanna inhabitant. Humans lack sun-reflecting fur, but have thermo-insulative subcutaneous fat layers, which are never seen in savanna mammals. We have a water- and sodium-wasting cooling system of abundant sweat glands, totally unfit for a dry environment. Our maximal urine concentration is much too low for a savanna-dwelling mammal. We need much more water than other primates, and have to drink more often than savanna inhabitants, yet we cannot drink large quantities at a time.
  • Maps of human population densities show that, although we have become fully terrestrial today, we are still a waterside species, and almost half of human dietary calories still come from the water (e.g. rice, aquaculture, fish, shell- and crayfish).

I find the water-drinking point especially persuasive. We need to drink throughout the day, or at least feel bad if we cannot. Almost all workplaces, including cafes, have a source of water. This is inconsistent with savanna living and consistent with waterside living. The term aquatic ape is somewhat misleading. A better name would be aquatic-food ape.

Consistent- versus Inconsistent-Handed Predicts Better than Right- versus Left-Handed

Tuesday, February 26th, 2013

At Berkeley, Andrew Gelman and I taught a freshman seminar about left-handedness. Half the students were left-handed. We did two fascinating studies with them that found that left-handers tend to have left-handed friends. I kick myself for not publishing those results, which I bring up in conversation again and again.

After the class ended I got a call from a journalist who was writing an article about ridiculous classes. I told him the left-handedness class had value as a way of introducing methodological issues but all I cared about was that his article be accurate. He decided not to include our class in his examples.

Stephen Christman, who got his Ph.D. from Berkeley (and did quirky interesting stuff even as a graduate student), and two colleagues have now published a paper that is a considerable step forward in the understanding of handedness. They argue that what really matters is not direction of handedness but the consistency of it. The terms left-handed and right-handed hide a confounding. Right-handers almost all have very consistent handedness (they do everything with the right hand). In contrast, left-handers much more often have inconsistent handedness: they do some things with the left hand, some with the right. I am a good example. I write with my right hand, bat and throw left-handed, play tennis left-handed, ping-pong right-handed. In fact, I am right-wristed and left-armed. When something involves wrist movement (writing, ping-pong) I use my right hand. When something involves arm movement (batting, throwing a ball, tennis), I use my left hand. Right-handers are much more similar to each other than left-handers.

Christman and his co-authors point to two things: 1. When you can get enough subjects to unconfound the two variables, it turns out that consistency of handedness is what makes the difference. Consistent left-handers resemble consistent right-handers.  2. Consistency of handedness predicts many things. Inconsistent-handers are less authoritarian than consistent-handers. They show more of a placebo effect. They have better memory for paragraphs. And on and on — about 20 differences. It isn’t easy to say what all these differences have in common but maybe inconsistent-handers are more flexible in their beliefs. (Which would explain the friendship findings in our handedness class.)

I think about these differences as another example of how every economy needs diversity and our brains have been shaped to provide it, one idea underlying my theory of human evolution. Presidents of the United States are left-handed much more than the general population. For example, Obama is left-handed. The difference between Presidents and everyone else is overwhelming and must mean something. Yet left-handers die younger. I would say that in any group of people you need a certain fraction, not necessarily large, to be open-minded and realistic. That describes inconsistent-handers (who are usually left-handed). These people make good leaders because they will respond to changing conditions. People who are not open-minded make good followers. Just as important as realism is cooperation, ability to work together toward a common goal.


No More Antixoxidants

Tuesday, November 20th, 2012

This fascinating blog post by Josh Mittledorf points out that antioxidants, once believed to reduce aging by reducing oxidative damage, have turned out to have the opposite effect. By reducing a hormetic effect, they make things worse. I’m a friend of Bruce Ames, one of main proponents of the free radical theory of aging. I’ve heard him talk about it a dozen times. The turning point — the beginning of the realization that this might be wrong — was this 1994 study, which found that beta-carotene, a potent antioxidant, increased mortality. Bruce did not have a good explanation for the counter-theoretical result. However, Mittledorf doesn’t mention an important fact which doesn’t fit his picture. Selenium, a potent antioxidant, also powerfully reduces cancer. Don’t stop taking selenium.

I also like this theoretical paper by Mittledorf  about why aging evolved (turning off certain genes reduces aging) and how its evolution — not easily explained by conventional evolutionary ideas — is part of a range of phenomena that the conventional ideas cannot explain. One reason, maybe the main reason, that aging is adaptive is very Jane Jacobsian: it makes the community more flexible. Less likely to repeat old ways of doing things.

Thanks to Ashish Mukarji.



Taobao’s Double Eleven: World’s Biggest eHoliday

Saturday, November 17th, 2012

Do the heads of eBay and Amazon know about the Chinese shopping site Taobao (like eBay without auctions)? If so, why don’t they imitate it? Maybe they can’t match its bigger selection (e.g., food, detergent) and better prices, but they could imitate the better seller feedback and instant communication (chat boxes) with sellers.

In my theory of human evolution I propose that we have ceremonies, rituals, and festivals (and associated holidays) because they caused trading that would otherwise not have taken place. Ceremonies and so forth increased the demand for certain goods — gifts and high-end clothes, for example. These goods are important economically far out of proportion to their volume or monetary value or daily use because they increase innovation. They help the most skilled artisans– the ones most likely to innovate — make a living.

The leaders of Taobao understand this function of festivals/holiday and have put it to use: They have created new festivals/holidays. The biggest is Double Eleven (November 11), which started five years ago. On Double Eleven, a large fraction of taobao merchants have discounts, big (50%) and small (5%). Sales have grown each year and this year reached about $3 billion, according to one site. According to a Chinese friend, the sales were about $10 billion. CyberMonday (about $1 billion in 2011) is far behind

I have never read about this function of ceremonies, festivals, etc., in any economics book or paper. Double Eleven shows their economic force. This neglect is an example of what I consider the biggest problem with modern economics: lack of attention to and lack of understanding of innovation.


Assorted Links

Friday, November 16th, 2012
  • Olive oil and the Willat Effect. “You can read about great olive oils, and their vast superiority over bad oils, all you want. . . . But until you try first-rate olive oil for yourself – actually put the good stuff in your mouth, and compare that experience to the bad stuff you’ve eaten in the past – you won’t really get it. . . . . Once you taste fine olive oils and their low-class imitations [side by side], though, you start to care.”
  • Petraeus Affair: The journalism of what we don’t know.
  • Tucker Max on book publishing. Disruptive innovation for popular authors.
  • Animal self-medication. Sick animals eat differently than healthy animals.

Thanks to Alex Blackwood.

The Power of the Willat Effect: Rinsed versus Unrinsed Tea

Saturday, November 10th, 2012

During my last visit to New York I bought a new black tea. I started drinking it a few weeks ago. I brewed it various ways (different amounts of tea, different steeping times, etc.) but had a hard time telling which way was best. This morning I decided I would learn how to  brew it by making paired comparisons (two cups of tea made the same way at the same time except for one difference). The fascinating thing, as I’ve said, about these side-by-side comparisons is that they produce hedonic changes. They change how much you like this or that. I call this the Willat Effect after my friend Carl Willat who caused me to notice it.

This morning I made two cups of the new tea. The two cups were brewed the same except in one case I “rinsed” the tea before brewing. Rinsing means I poured a bit of hot water on it and quickly got rid of the hot water. Rinsing tea removes from the final product whatever is transferred from the tea to the hot water in the first few seconds. In China, rinsing tea is common; in the United States, very rare.

I tasted the two cups (rinsed and unrinsed) side by side. The rinsed tea tasted much better. The unrinsed tea had something weird about it. Ugh, I thought, I can’t drink this. I threw out the unrinsed tea. Over the previous few weeks, I had happily drunk the new tea unrinsed many times. Now I found it repulsive.

Assorted Links

Thursday, August 23rd, 2012

Thanks to Adam Clemens.

How I Will Teach Next Semester: Human Evolution and College Teaching

Thursday, May 31st, 2012

I have wondered for a long time how to apply my ideas about human evolution to teaching. My theory of human evolution says that specialization and trading are central to human evolution and includes a mechanism that increases diversity of expertise. The more diverse the expertise of you and your trading partners, the more you gain from trading. If I make knives and you make knives, we will gain less from trading than if I make knives and you make baskets.

I also discovered — independently — that the more choice I gave my Berkeley students (junior and senior psychology majors) about what to learn, the more they learned. It was as if they had an internal drive to learn all sorts of different things and the more I allowed that motivation to push and guide them, the more they learned. To see big effects it wasn’t enough to merely give them a wide choice of term paper topics (as many college teachers do). I pushed them out into the “real” (off-campus) world (they couldn’t do a library project) and said learn whatever you want. In this situation they learned an enormous amount. The connection with my theory of evolution was obvious: something inside of them was pushing them to be diverse in what they learned. What they learn = what they will become expert in. What they become expert in = what they will have to trade.

The more I allowed the underlying diversity of my students to be expressed, the more they learned. Yet almost all college classes treat all of the students in the class the same: same material, same assignments, same tests. The diversity of the students — especially the ways they differ from the professor — is a nuisance. So my theory suggests that standard college teaching is greatly at odds with human nature. It assumes one size fits all when that could hardly be more wrong.  It should be possible to greatly increase how much is learned by doing a better job of recognizing human nature. My experience so far supports this prediction.

Recently I thought of a new way to deal with diversity among my students. Next semester I will try it. One of the courses I am teaching (at Tsinghua University) is Frontiers of Psychology, with about 25 students. It’s required of freshman psychology majors. Here’s what I’ll do. For the first four or five class periods (one class per week), I’ll cover a wide range of psychological topics, ideas, and methods. There will be reading assignments (e.g., choose one paper out of 30 and do a class presentation) but no grading. Then every student will draw up a list of “learning goals” for the rest of the semester.  The goals can be whatever they want (related to psychology). They can read a book, read some articles, collect some data, give a talk to a high school class, whatever. Each goal will have a deadline. The assessment will be binary: goal completed/not completed. Their final grade will depend on how many goals they completed. The goals will be ordered. The further down their list they get, the higher their grade, with each level of completion assigned a grade at the beginning. They will make class presentations throughout the semester about their progress: what they are doing, what they have learned.

For the students, the benefits (compared to conventional teaching) are that (a) they get to learn exactly what they want yet (b) the grading criteria are very clear and (c) they are still motivated to work. For me, the benefits are that it should be a lot easier to judge if a goal has been completed than to grade homework essays, which is what I’ve done recently. Nor will I have to worry about what happens in class each week.

Any comments?

Medieval Metallurgy, the Evolution of Decoration, and the Shangri-La Diet

Friday, May 25th, 2012

A new BBC series Metalworks! is about the history of British metal working. My theory of human evolution says that decoration — more precisely, our enjoyment of it — evolved because it helped the most skilled craftsmen make a living. Long ago, technology evolved via massive amounts of trial and error, which required subsidy since payoff (discovery with practical value) was so infrequent. It was much easier to discover/learn how to make something that looked better than something that worked better, but the two sorts of discoveries were correlated: trial and error produces both.

The episode on ironwork (The Blacksmith’s Tale) makes explicit how desire for decoration made it easier for the most skilled iron workers to make a living:

[Expert, at 16:50:] “I think decoration entirely depends on the amount of money the patron wanted to spend on that particular object.” [Narrator:] By the end of the 15th Century, wealthy patrons, such as the Church and monarchy, were hand-picking known craftsmen at the top of their game to match a commission’s requirements. When King Edward IV commissioned the Cornish smith John Tresillion to make these Gothic gates at Windsor in 1497, he did so with good reason. . . . [Expert:] “No blacksmith, ordinary blacksmith who was used to making horseshoes, could dream of working to this standard of perfection.”

Quality of decoration is easy to see. It doesn’t matter but it correlates with something that does matter — amount of trial and error (more trial and error, more innovation). We reward decoration to increase innovation.

The Shangri-La Diet derives from a theory of weight control that emphasizes smell-calorie learning. Smell-calorie learning evolved for the same logical reason. Smells don’t actually matter for health. But they are easy to notice and they correlate with things that do matter for health, such as calories. Via smell-calorie learning we learn the correlations. After that the foods that smell best are the ones that contain more calories.