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Catching Fire. February 15, 2021

This book offers a compelling case for the idea that cooking is the main reason why we evolved from australopithecines to Homo erectus and then to Homo sapiens. It challenges at several points the mainstream notion that meat-eating was a keystone of (at least some parts of) this evolution, for having comparatively limited explanatory power. Besides the anatomical changes it uses cooking to explain some things I wouldn’t have expected, such as marriage and the sexual division of labor.

I thought the point was generally well-argued and at the same time the book provided enough interesting bits to keep a wide audience interested. There are plenty of anecdotes (favorite example: the author adds tough leaves to a raw goat meat meal to test that they make chewing easier), and many references to actual studies in the endnotes for the true nerds.

It has a problem that might be unavoidable in this kind of pop-sci book: there’s always a lot of uncertainty in modern science (especially in something with as little archeological evidence as fire), but, because the author wants to make their case as persuasive as possible, diverging points tend to be omitted or minimized. As a result, it’s sometimes hard to know what’s well established and what’s controversial. For example, a core point in the book (why is the human brain so unusually large?) relies on the Expensive tissue hypothesis. The author does note that it’s a hypothesis, but there’s no exploration of why it’s still one, or how accepted it is in the field.

I wrote a summary of each chapter, plus notes on bits I find interesting and references.

The Cooking Hypothesis

Man evolved from australopithecines into habilines and then to Homo erectus and then to Homo sapiens. A popular theory to explain how that took place is that we evolved to hunt meat. Hunting would’ve required a degree of tool development and cooperation that australopithecines wouldn’t have been capable of.

This theory fails to explain how this evolution would also have enabled gathering, which is crucial to make the hunting lifestyle possible. (Sometimes you come back empty-handed from a hunt.) It also fails to explain how the jump to Homo erectus, who had an upright posture and weaker jaws and teeth than their predecessors, could have evolved from habilines. Could cooking explain that evolution? The answer this book provides is yes.

Quest for Raw-Foodists

Like other animals, humans can live off a completely raw food-based diet. However, it seems that we have a hard time getting enough energy from raw food alone. There have been experiments where people have gone on a raw food-only diet, such as the Evo Diet experiment, and they always end with people having lost weight. A more striking example is the Giessen raw food study, which had the further result that about half of the women in completely raw food diets had stopped menstruating. Such a strong effect on reproductive function indicates that we have evolved to eat cooked food.

There aren’t concrete reports of any cultures that survive exclusively on raw food. Some eat more raw food than others, but all societies seem to rely on cooking. There are also no examples of people surviving long-term on raw food (except perhaps Helena Valero, who claimed to have lived off bananas for 7 months.)

The Cook’s Body

Why did we evolve to eat cooked food and lost the ability to process raw food efficiently? It could be an evolutionary tradeoff. First, once we started cooking we immediately got the benefits from the extra energy cooked food provides. Then, we evolved a smaller digestive system, which allowed to process cooked food more efficiently. At that point we lost the ability to live off raw food.

There’s ample evidence supporting the first step: many examples of animals (including insects) that grow better on cooked food. For the second step, we can observe that we have much smaller mouths than our relatives (for example, chimpanzees can open their mouths twice as wide as humans), tiny lips and much weaker jaws. Our stomachs are also very small, which makes sense given the high caloric density of cooked food, and our large intestines are about half the size of what a primate with our body weight normally would be, which explains why we can’t process plant fiber as efficiently as great apes.

Could these changes be explained by us having evolved to eat meat instead? Our mouths and jaws aren’t very good at eating raw meat. Also, we don’t keep food in our stomachs for a very long time, which is important for digesting raw meat. (For example, cats keep food in their stomach from five to six hours; for humans, it’s one or two.) More importantly, plants would have been a key component in the diet of tropical hunter-gatherers, so meat-eating alone cannot explain why they would have evolved such small digestive systems.

Another interesting bit: we seem to have some resistance to Maillard compounds, such as acrylamide, which has been shown to be carcinogenic in animal models. Maillard compounds are a by-product of cooking (in particular overcooking), so this could be evidence that we evolved for cooked food. By contrast, we have very little resistance to bacteria that live on raw meat.

Tags. October 20, 2019

This blog now has tags. It was just a matter of adding a taxonomy to config.toml and adding the tags to the entries in the org-mode file where the source for this blog lives and letting ox-hugo do its magic.

Catch-22. October 20, 2019

This book is not an easy pick up—it starts confusing and never really settles. But I recommend you do anyway, because it’s everything at once: funny and tragic, logical and absurd.

This was my second time reading this book, and I’ve been thinking about why it still wasn’t a very easy read, and why despite of that I like it even more than the first time around. The non-chronological narrative definitely doesn’t make it any easier, and there’s also a lot of characters to follow.

But I think the main factor is how the absurdity of it all is emphasized over and over. The first time the term Catch-22 is introduced, it’s just a single funny thing among all the absurd things going on. We only know it’s significant because it’s also the title of the book. But the absurdity keeps ramping up to new levels up to the point where you realize that the characters are actually quite sensible, given the circumstances. And then the book drops another bomb of insanity.

Coders and stereotypes October 13, 2019

Postlight’s podcast Track Changes has an interesting interview this week with Clive Thompson about his new book, Coders: The Making of a New Tribe and the Remaking of the World. The focus of the book is the people writing the code that drives some of the biggest companies of our era, as opposed to the leaders of those companies, who tend to get a lot more media attention.

The highlight for me was the discussion of how coders actually think, as opposed to popular stereotypes.

Clive Thompson: I think there’s around 200 developers I spoke to, ranging from hanging out with a bunch of them in a bar at a conference, to talking for hours to one person and profiling them. One of the things I was trying to do was, what are the actual common threads, what makes them tick, why they like this, why they get into it. Some of the things people think are maybe kind of obvious, like, they’re very logical thinkers! Well, you know, they kind of have to be. If you can’t think systematically and logically, this isn’t going to work out very well.

So there was this obvious stuff. But actually what intrigued me was one of the more unexpected things. I began to realize when talking to them that these are people that have an ability to endure a grinding level of frustration that’s an order of magnitude higher than what most human beings can handle.

Paul Ford: My joke is, someone works in this field if they have a callus in their finger from reloading over and over again. You have to get into a zone where you can look at something 5-600 times over and over again over the course of a couple hours and just incrementally change or update it.

Clive Thompson: What people don’t get about writing software is how all these images in Hollywood of someone sitting down and typing and it just pours out, and they don’t know that actually what you’re doing is fixing broken stuff. The function you just wrote already isn’t working. And then there’s a codebase you inherited–uncommented, weird COBOL from 20 years ago and you gotta figure that out. The daily life of most developers is just sitting around, staring at things that don’t work and somehow being able to smash their forehead through the wall to get that.

(…)

Clive Thompson: [There’s] this desire to constantly tweak and improve and render more efficient and more optimized. Everyone would tell me about how it happened early on when they were learning to program when they sort of realized, “Christ! Computers are really good at taking these repetitive actions, and things that are being done slowly and speed them up” and then they just start developing this X-ray vision and they can’t turn it off. Everything they see needs to get more efficient. There was this one woman, who worked for Zillow. We were hanging out in San Francisco and she was like, “On the way here I was standing at the corner and watching people cross the street and I almost felt like screaming at them because I felt they were doing it in a suboptimal way.” She’s like, “I’m out of my mind”.

Paul Ford: Eh, it’s San Francisco, I think maybe people would welcome it.

I thinks this gets more into the mind of a programmer than most of what I’ve read on the subject (and a lot of it was written by technical people!) There’s a lot more insight in the episode, definitely recommended. And probably the book as well. (Which I’ll definitely read at some point–I just need a break from tech books right now.)

Catch-22, deontologism and consequentialism October 13, 2019

I’ve been rereading Catch-22 (and loving it). I’ve also been reading random pages on the Stanford Encyclopedia of Philosophy. The other day was checking out Kant, which led me to the page on Deontological ethics and its relation to consequentialism.

Very short summary: consequentialism says that to know whether an action is right or wrong, we should look at the consequences of that action. Deontology, on the other hand, looks at the action itself and judgets it according to a set of rules.

As someone who doesn’t know much about philosophy, I find that a useful way to remember concepts is to try to apply them to whatever is happening in my life at the time. Which in this case was Catch-22.

The characters in Catch-22 are so full of contradictions that it might be silly to apply ethical theories to them. But I want to do it anyway.

I had just read the chapters on Milo Minderbinder (who has Wikipedia page) and his syndicate. To me, Milo seems profoundly consequentialist:

“Milo, how do you do it?” Yossarian inquired with laughing amazement and admiration. “You fill out a flight plan for one place and then you go to another. Don’t the people in the control towers ever raise hell?”

“They all belong to the syndicate,” Milo said. “And they know that what’s good for the syndicate is good for the country, because that’s what makes Sammy run. The men in the control towers have a share, too, and that’s why they have to do whatever they can to help the syndicate.”

Of course you could say that he’s doing it all for personal gain, but the story he tells himself and others is that it’s all for the greater good. He could probably also argue well for it: he’s loved in a lot of places for bringing business there:

Milo had been elected mayor of Palermo—and of nearby Carini, Monreale, Bagheria, Termini Imerese, Cefalù, Mistretta and Nicosia as well—because he had brought Scotch to Sicily.

Later, he makes a bad business decision—buying all cotton in Egypt—, and his company verges on collapse. He finds a way out: bombing his own squadron.

This time Milo had gone too far. Bombing his own men and planes was more than even the most phlegmatic observer could stomach, and it looked like the end for him. High-ranking government officials poured in to investigate. Newspapers inveighed against Milo with glaring headlines, and Congressmen denounced the atrocity in stentorian wrath and clamored for punishment. Mothers with children in the service organized into militant groups and demanded revenge. Not one voice was raised in his defense. Decent people everywhere were affronted, and Milo was all washed up until he opened his books to the public and disclosed the tremendous profit he had made. He could reimburse the government for all the people and property he had destroyed and still have enough money left over to continue buying Egyptian cotton. Everybody, of course, owned a share. And the sweetest part of the whole deal was that there really was no need to reimburse the government at all.

Yossarian, on the other hand, seems to be more of a deontologist. He’s against Milo’s deals with the Germans, merely because they’re at war with the Germans and one shouldn’t deal with the enemy:

Milo was appealing to Yossarian from the bottom of his soul. “Look, I didn’t start this war, Yossarian. (…) If I can persuade the Germans to pay me a thousand dollars for every plane they shoot down, why shouldn’t I take it?”

“Because you’re dealing with the enemy, that’s why. Can’t you understand that we’re fighting a war? People are dying. Look around you, for Christ’s sake!”

It’s not like Yossarian is particularly committed to the war effort, really. He thinks everyone is out to kill him and goes to great lengths to avoid combat (“He was going to live forever, or die in the attempt”). But there’s still an internal set of rules he seems to be following. For example, he refuses to help Dobbs kill Colonel Cathcart, who keeps raising the number of missions and preventing him from going home:

“I don’t think I could do it,” Yossarian concluded, after weighing the idea in silence awhile.

Dobbs was astonished. “Why not?”

“Look. Nothing would please me more than to have the son of a bitch break his neck or get killed in a crash or to find out that someone else had shot him to death. But I don’t think I could kill him.”

“He’d do it to you,” Dobbs argued. “In fact, you’re the one who told me he is doing it to us by keeping us in combat so long.”

“But I don’t think I could do it to him. He’s got a right to live, too, I guess.”

Pluralistic ignorance. June 2, 2019

Pluralistic ignorance is a perverse phenomenon where most people are against a certain social norm, but support it anyway because it is the socially acceptable thing to do.

The paper ‘Everybody’s doing it’: on the persistence of bad social norms (via @DegenRolf) proposes an interesting little experiment where they can test the effect of group size, conformity and information has on the prevalence of bad norms. Not surprisingly, it’s easier to put away bad norms in smaller groups and it’s very hard to break away from a bad norm that’s widely accepted.

Interestingly, pluralistic ignorance seems to be very dependent on incomplete information; when subjects were allowed to communicate, the bad norm went away very quickly. This gives me hope that we can fix a lot just by letting people speak out more.

The Nordic paradox. May 27, 2019

Nordic countries have relatively high rates of violence against women, which is puzzling because they also have very high gender equality. When I first heard of this, my first thought was that surely, there’s a lot more reporting in those countries, so of course you get more cases.

This article seems to address that:

89.1% of the Swedish sample had higher values in the physical IPVAW factor than the Spanish average, and this percentage was 99.4% for the sexual IPVAW factor as compared to the Spanish average. In terms of probability of superiority, there was an 80.7% and 96.1% probability that a Swedish woman would score higher than a Spanish woman in the physical and the sexual IPVAW factors, respectively. Our results showed that the higher prevalence of physical and sexual IPVAW in Sweden than in Spain reflects actual differences and are not the result of measurement bias, supporting the idea of the Nordic paradox.

I’ll have to dig in a bit deeper to understand the methods they used to exclude the possibility that the difference is just due to reporting (“measurement bias”), but if it really holds, then I have no idea how to explain the paradox.

Books do work, but they take a lot of work May 14, 2019

Interesting food for thought from Andy Matuschak:

Picture some serious non-fiction tomes. The Selfish Gene; Thinking, Fast and Slow; Guns, Germs, and Steel; etc. Have you ever had a book like this—one you’d read—come up in conversation, only to discover that you’d absorbed what amounts to a few sentences? I’ll be honest: it happens to me regularly.

Matuschak goes on to argue that understanding1 somethings requires engaging with it in some substantial way. Indeed, I’ve read the three books mentioned, and the only one I can meaningfully talk about is Guns, Germs and Steel. I’m pretty sure that’s due some brief discussions I’ve had about the book’s ideas while reading it, many years ago.

While reading the post I was wondering what he thinks about Michael Nielsen’s ideas on using spaced repetition to explain concepts. Then at the end I found that they collaborated on a book that does exactly that.

I have to say, though, that I’m satisfied with the current situation. Maybe there is no way to significantly improve our learning from books without putting in the work, but if it’s worth it then I have no trouble putting in the work. A bigger issue to me is that there are so many sources of information today that putting in the work in any one of them doesn’t seem worth it (since I could spend my time superficially learning other things).

That touches on perhaps my main issue with popsci books: if the subject is interesting and the reading is said to be pleasing, then I’ll be tempted to read them, but I know that precisely because they’re easy to read, I never have to engage actively with them and so I largely forget them as soon as I’m done with them. Tougher books require you to put more work into them, but that’s what you need if you want to remember anyway. I find it hard to believe that spaced repetition can help here if it happens seamlessly as you read.


  1. I’d prefer to say “remembering”, if only because “understanding” has a nearly magical connotation to me. ↩︎

Wikipedia and rats. April 7, 2019

Next time I see a banner on Wikipedia asks me to donate, I’ll be thinking of this:

If everyone reading Wikipedia donated the cost of a cup of coffee, this debate could’ve gone forever!

Don’t get me wrong, I love Wikipedia and have donated to it. Where else could I get trivia as random as this:

On the Isle of Man, there is a taboo against the word “rat”.

Nabokov as a refugee. April 4, 2019

Interesting article from the NYT about Nabokov. Not knowing much about his life other than he was Russian and lived in the US later in life, I was surprised by some of the information here; for example, after leaving Russia, he traveled with a Nansen passport (issued to stateless persons), he and his wife having been stripped of Russian citizenship. The article actually shows a US immigrant identification card with his nationality stated as without. And then this:

And then there was “Dr. Zhivago.” Published four weeks after “Lolita,” it joined Nabokov’s masterpiece at the top of the 1958 best-seller list. Nabokov wrote off Boris Pasternak’s novel as “wretched and mediocre,” or, on a better day, as “a sorry thing, clumsy, trivial, and melodramatic.” He might shrug off his losses, but 1919 still burned bright: He could not forgive Pasternak for having raced past the liberal revolution on his way to writing about the Bolshevik coup. The Nabokovs knew a Soviet plot when they saw one: They were convinced the Communists had pretended to smuggle Pasternak’s novel out of the Soviet Union. Its American publication amounted to a cunning act of currency conversion. Nabokov forbade his publisher from mentioning him and Pasternak in the same breath. It was as if the Cold War played out weekly in America’s bookstores.

I knew he had strong opinions about other writers, but this degree of paranoia makes him sound a bit like some of his characters.