Category: human evolution

My Theory of Human Evolution (the pleasure of crafts)

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On the Meet the Pros episode of This American Life, David Rakoff said

I make stuff: boxes, lamps, mirrors, small folding screens, painted jackets for kids, that sort of thing. It’s what I do in my spare time. Some people exercise; my salvation lies in time spent alone with an Xacto knife and commercial-grade adhesive. During the act of making something, I experience a kind of blissful absence of self and a loss of time. I almost cannot get this feeling any other way. . . . I once spent 16 hours making 150 wedding invitations by hand and was not for one instant of that day tempted to check the time.

He gives the stuff he makes as gifts to his friends. A Martha Stewart Living staffer tells Rakoff it is harder to do this sort of thing for a living than as a hobby.

My theory of human evolution, which explains how we became the only species whose members make their living in many diverse ways, says the sequence was: 1. Hobbies. 2. Part-time jobs. 3. Full-time jobs. The first hobbies obviously involved making things and were the beginnings of craftsmanship. That many of us, such as Rakoff, enjoy crafts indicates that those early genes are still there.

Before trading evolved, you gave the products of your specialized skill to your friends, which generated a vague obligation. This was the precursor of trading. In contrast to trading, of course, in this case the recipients may have only a little use for what they receive.

Modern Veblen: The Less-Than-Obvious Value of Evolutionary Explanations

Seth Roberts2 Comments

An interesting Economist article about sex differences in a visual task calls an evolutionary explanation a “just-so story.” I don’t know if the late Stephen Jay Gould, evolutionary theorist, Harvard professor, and “one of the most influential and widely-read writers of popular science of his generation” (Wikipedia), invented this form of dismissal, but certainly he was fond of it. Here, for example:

Evolutionary biology has been severely hampered by a speculative style of argument that . . . tries to construct historical or adaptive explanations for why this bone looked like that or why this creature lived here. These speculations have been charitably called “scenarios”; they are often more contemptuously, and rightly, labeled “stories” (or “just-so stories” if they rely on the fallacious assumption that everything exists for a purpose). Scientists know that these tales are stories; unfortunately, they are presented in the professional literature where they are taken too seriously and literally.

Well, this is seriously wrong. My work contains several just-so stories — evolutionary explanations of the morning-faces effect and of the mechanism behind the Shangri-La Diet, for example. My theory of human evolution might be called a just-so saga.

These explanations made me (at least) believe more strongly in the result or theory they explained — which turned out to be a good thing. My morning-faces result was at first exceedingly implausible. The evolutionary explanation encouraged me to study it more. After repeating it hundreds of times I no longer need the evolutionary explanation to believe it but the explanation may help convince others to take it seriously. The evolutionary explanation connected with the Shangri-La Diet had the same effect. My evolutionary explanation of the effect of breakfast on sleep led me to do the experiment that discovered the morning-faces effect. My theory of human evolution led me to try new ways of teaching, with good results.

Why did Gould make this mistake? Thorstein Veblen wrote about our fondness for “invidious comparisons.” We like to say our X is better than someone else’s X. Sure, evolutionary explanations may be hard to test. That doesn’t mean they’re worthless. Like many scientists, Gould failed to grasp that something is better than nothing.

Addendum: Perhaps the Economist writer had read a recent Bad Science column that began:

I want you to know that I love evolutionary psychologists, because the ideas, like “girls prefer pink because they need to be better at hunting berries” are so much fun. Sure there are problems, like, we don’t know a lot about life in the pleistocene period through which humans evolved; their claims sound a bit like “just so” stories, relying on their own internal, circular logic; the existing evidence for genetic influence on behaviour, emotion, and cognition, is coarse; they only pick the behaviours which they think they can explain while leaving the rest; and they get themselves in massive trouble as soon as they go beyond examining broad categories of human behaviors across societies and cultures, becoming crassly ethnocentric.

“They only pick the behaviours which they think they can explain” — how dare they!

My Theory of Human Evolution (quasi-reinforcement edition)

Seth Roberts3 Comments

My theory of human evolution assumes that art evolved because it acted like a ramp. It helped bridge the technical gap between one useful tool and the next. Tools have the property that almost all the necessary knowledge is no help. If you have 90% of the technical knowledge you need to build a gun, you can’t build a gun that works 90% as well as an actual gun; in fact, you won’t be able to build a useful gun at all. The point is even clearer with computers: Until you have a vast amount of technical knowledge, you can’t build even the crudest possible computer. When you finally get enough knowledge to build a very crude but working version, then increases in technical knowledge will help you improve it. But eventually you will reach a ceiling where more technical knowledge has little payoff. This state of affairs is shown by the “without art” function of this graph:

the function of art

Art is different. Because we value novelty in art, and improvements in technology have obvious effects (e.g., new colors, brighter colors, sharper lines), each little improvement in technology — in the “state of the art” — is rewarded, long before that increase in knowledge helps build something more conventionally useful. Artists were the first material scientists.

Support for my assumption that evolution can build such ramps comes from a little-known psychological effect called quasi-reinforcement discovered by Allen Neuringer and Shin-Ho Chung. Suppose you require a pigeon to peck a key 300 times to get food. It will peck, but slowly. Now you change the situation so that every 20 pecks a light comes on for a few seconds. Although the pigeon will not peck a key simply to turn on a light, this change will roughly double the peck rate — a huge increase given that food per peck hasn’t changed. It’s like doubling the amount of work you get from an employee without a salary increase. I use this effect daily. Given any large task, I break it into much smaller tasks and mark the completion of each one. A friend of mine found it helped to make a mark on a piece of paper each time she read a textbook page. The quasi-reinforcement effect is essentially a ramp that helps us do long tasks that would otherwise pay off only when completed.

To me, blogging is a kind of ramp: It breaks a big task (e.g., writing about my omega-3 research) into much smaller parts with reward after each one.

My Theory of Human Evolution (guitar edition)

Seth Roberts1 Comment

In this podcast, New Yorker writer Burkhard Bilger talks about the guitars of Ken Parker. A lot of research goes into them. I propose that we enjoy music because enjoyment of music creates demand for musical instruments, which leads to material-science research. My previous earlier posts about human evolution have said something like this — art generates research — several times. Previous examples were visual.

Josh McDermott, a psychologist at MIT, has compared human and animal responses to music. From an in-press paper:
When presented with a choice between slow tempo musical stimuli, including lullabies, and silence, tamarins and marmosets preferred silence whereas humans, when similarly tested, preferred music. . . .There appear to be motivational ties to music that are uniquely human.

A Novelist on the Aquatic Ape Theory of Evolution

Seth Roberts1 Comment

Plausibility of the Aquatic Ape Theory of Human Evolution is one reason I started studying the effects of omega-3s. Novelist Elizabeth Bear doesn’t like it:

[Doris] Lessing appears to have drawn her background from Elaine Morgan’s notorious pseudoscientific tome, The Descent of Woman (1972), which argues that human evolution was shaped by a seal-like return to the sea. Crackpot theories can make for great fiction but in this case . . .

That I found beneficial effects of omega-3s many times supports the “crackpot” theory.

My Theory of Human Evolution (Planet Earth edition)

Seth Roberts5 Comments

The many-hour BBC documentary Planet Earth, mentioned earlier, takes viewers way off the beaten track — deep into giant caves, for example. But humans — and human evolution — creep in.

Non-human primates are shown a dozen-odd times during the series. Only once do we see them walk erect: When baboons wade into a flooded area of Africa. This adds credence to the Aquatic Ape theory of human evolution, which assumes our ancestors came to walk upright because it helped them walk in water. David Attenborough, Planet Earth‘s narrator, made an excellent radio show about the Aquatic Ape theory.

The Aquatic Ape theory explains all sorts of physical differences between man and our closest primate ancestors — why we walk upright and they don’t, for example. My ideas about human evolution are about what happened next. I try to explain ways we differ mentally from other primates — we speak, for example. The core idea of my theory is that the human brain has changed in many ways to promote occupational specialization. For example, language — single words — began because it facilitated trade; it was the first advertising. (I think of a Guatemalan market where someone shouted “toothpaste” over and over. He was selling toothpaste.)

The magic of occupational specialization also comes up in Planet Earth. The “Planet Earth Diaries” (Making-of) section of “Seasonal Forests” describes filming baobab trees using a unique hot-air balloon designed for photography by Dany Cleyet-Marrel and piloted by him. Twice he flies into trees by mistake. “Many of Planet Earth‘s finest images would have been impossible without devoted and passionate specialists like Dany,” says Attenborough.

Art and Commerce

Seth Roberts5 Comments

A fascinating discussion about the art and business of pottery, such as:

I used to make bowls of many colors, then one day I realized that my stock of colors of bowls on the shelves was increasing, but I had no blue bowls. It dawned on me that I was selling off everything blue, and bringing home all the other colors. So I now make only blue stuff. And mostly bowls. Why? 95% of my customers are ladies, and every lady needs a good bowl. And it shows in my sales. Now, I confess to playing a bit now and then and making the occasional ornamental bean pot, or platter, or bread baker. But those are not my mainstay. That is bowls. Bowls and pots with a commercial attitude …. I stay away from art and craft shows – too expensive for what they do. I try and sell in a fifty mile radius of where I live and that seems to work. And I try to simply make good pots.

Veblen’s Instinct of Workmanship.

How to Be a Grown-up About Evolution

Seth Roberts4 Comments

Spy magazine had a wonderful column by Ellis Weiner called “How to Be a Grown-up”. (In one column, Weiner pointed out that homeless, applied to beggars, should be houseless.) Gordy Slack, a Bay Area science writer, has written the first book that might be called How to be a Grown-up About Evolution. It is an account of the Dover, PA trial in which parents sued the school board for requiring that intelligent design be mentioned in biology class. The actual title is The Battle Over the Meaning of Everything. (I’ve known Gordy for years and he wrote about me for The Scientist.)

Not surprisingly, Gordy sympathizes with the parents (the anti-creationists). But he tries to understand the other side rather than demonize it, which is what is grown-up about his book. One reason for this attitude is that his father is on the other side. His father, at one point a professor of psychology at Harvard, became at age 51 a born-again Christian and a creationist. In 1998, his father took Gordy to meet Philip Johnson, the Berkeley law professor who is the father of intelligent design (ID), a big-tent version of creationism. “Give us five or ten years, and you’ll see scientific breakthroughs biologists hadn’t dreamed of before ID,” Johnson told Gordy.

While writing the book, Gordy happened to interview Joan Roughgarden, a Stanford biology professor whose specialty is evolution.

I thought our interview was going well. But when I told her that I was writing a book about ID in order to understand what drove its proponents, her attitude and demeanor swung around 180 degrees. . . .”They want to define me [Roughgarden is a transsexual] as inhuman,” she said.

How dare anyone try to understand the other side! (Roughgarden’s reaction to a psychology talk she didn’t like.) The notion that the solution to intolerance is more intolerance is remarkably popular, which is why The Battle Over the Meaning of Everything really stands out.

Gordy’s blog.

My Theory of Human Evolution (amazon.com edition)

Seth Roberts3 Comments

For a birthday present, I bought Planet Earth, a beautiful and eloquent 5-DVD documentary, from amazon.com. I had it gift-wrapped. It looked like this:

my gift alone

I was amused. This is not how gifts should look. It looked machine-wrapped; gifts should look hand-wrapped. They should look like lots of care went into the wrapping. I thought everyone knew this, but the gift-wrap designers at amazon.com appear to be unclear on the concept. At least use intricate wrapping paper, would have been my advice. Here is my gift among the other gifts:

Why do we want gifts to be intricately wrapped? It is part of a whole gift-giving ethos. Sure, gifts must be (slightly) difficult otherwise they are meaningless. But that’s not the whole story. The signaling explanation of gifts (gifts show we care) is not the whole explanation because there are many ways to be difficult, only some of which advance material science. Do we like gifts to be old — to be aged, to have sat in our closet for 5 years? That would be difficult, but it wouldn’t advance material science. Do we like gifts to be very new (“fresh”) — made that morning? That too would be difficult but wouldn’t advance material science. Do we like gifts to be made by very old or very young people? That too would be difficult but wouldn’t advance material science. Whereas the actual desire for intricacy does advance material science. To produce more intricate designs, you need better control of your materials. The most intricate objects are made by specialists — artists and artisans. Our desire for intricacy supports them (we can buy a nicer gift than we can make) and pushes them to improve their skills.

When Bill McKibben, an excellent writer, calls for homemade Christmas presents, I believe he is missing this point. In Berkeley, at least, local artisans, such as ceramicists, must make most of their money in Christmas season. (I should ask some of them about this.)

The evolutionary basis of Christmas.