

Astral Codex Ten Podcast
Jeremiah
The official audio version of Astral Codex Ten, with an archive of posts from Slate Star Codex. It's just me reading Scott Alexander's blog posts.
Episodes
Mentioned books

Jun 19, 2021 • 37min
Your Book Review: Plagues And Peoples
https://astralcodexten.substack.com/p/your-book-review-plagues-and-peoples [This is the seventeenth of seventeen finalists in the book review contest. This one was chosen out of the reviews I somehow missed the first time around. There were four other such essays, which you can see in a supplementary runners-up packet here. I’ll make a post about how to vote tomorrow. - SA] Biological evolution was hijacked by cultural evolution; tools and language allowed humankind to upset the ecological balance in incredible ways. We should all know the story by now. Human grunts to other human and they agree to kill a wooly mammoth together and then grunt and agree to share the meat and then grunt and learn to make a spear and grunt and form a complex society and worldwide dominant species. Parasites and viruses are invisible and hard to grunt about. A lion, in contrast, is difficult not to grunt about. This book, Plagues and Peoples written by William H. McNeill in 1976, frames the entirety of human history and prehistory in the context of humankind’s relationship with microparasites and viruses. Communication, culture, tools, clothes, and shelter allowed humans to hunt dominantly, live anywhere, and deal with most ecological challenges- but microparasites remained elusively hard to deal with until modern times. This uneasy relationship with the invisible unconsciously shapes where human’s live, how civilizations form, and how societies are organized. At every step of humanity’s evolution, McNeill sees microparasites and viruses being one of the ‘fundamental parameters and determinants of human history.’

Jun 16, 2021 • 11min
On Cerebralab On Nutt/Carhart-Harris On Serotonin
https://astralcodexten.substack.com/p/on-cerebralab-on-nuttcarhart-harris [epistemic status: extremely speculative] George at CerebraLab has a new review of Nutt and Carhart-Harris's paper on serotonin receptors (I previously reviewed it here). Two points stood out that I had previously missed: First of all - predictive coding identifies suffering with prediction error. This conflicts with common sense. Suppose I tell you I'm going to stab you in the arm, you agree that I'm going to stab you in the arm, and then I stab you in the arm, and it hurts a lot. You predicted what would happen correctly, but you still suffered. The theory resolves this with a distinction between common-sense-level and neurological predictions: your brain is "set" to expect normal neurological feedback from your arm, and when it gets pain signals instead, that's a violated prediction, and this is the level on which prediction error = suffering. But there are other cases where the common-sense and neurological sense of predictions are more congruent. When you first step into a cold shower, you feel suffering, but after you've been in it a while you adjust your "predictions" and it's no longer as unpleasant. If you unexpectedly lost $25,000 it would come as an extremely unpleasant shock, but when you predictably have to pay the taxman $25,000 each year you grumblingly put up with it. The theory of "active inference" adds another layer of complexity here; it posits that sometimes your brain automatically resolves prediction error through action. If you were expecting to be well-balanced, but actually you're off-balance, you'll reflexively right yourself until you're where you expected to be. At its limit, this theory says that all action takes place through the creation and resolution of prediction errors - I stand up by "predicting" on a neurological level that I will stand up, and then my motor cortex tries to resolve the "error" by making me actually stand. (one remaining problem here is why and how some prediction errors get interpreted as rewards. If you get $1 million one day because you're a CEO and it's payday and that's how much you make every payday, you will not be especially happy. If you get $1 million because you're an ordinary middle-class person and a crypto billionaire semi-randomly decides to give you $1 million one day, you will be very happy. This has been traced to reward being dopamine-based prediction error in the nucleus accumbens, and the CEO was predicting his windfall while the gift recipient wasn't. This suggests there's still something we don't understand about prediction error and suffering). So one question is: for some given prediction error, how much do I suffer vs. adjust my predictions and stop feeling it vs. take action to resolve it? George's take on Carhart-Harris & Nutt is that this is influenced by the balance of 5-HT1A vs. 5-HT2A receptors - two different kinds of serotonin receptor. 5-HT1A is (to vastly oversimplify) the main target of antidepressants. The more strongly it's stimulated, the more likely you are to resolve prediction error by adjusting your predictions - the equivalent of stepping into a freezing shower, but then acclimating so that it feels okay. Suppose you're depressed/anxious/upset because your boss keeps yelling at you. With enough 5-HT1A activation, you're better able to - on a neurological level - adjust your world-model to include a prediction that your boss will yell at you. Then when your boss does yell at you, there's less prediction error and less suffering. This is good insofar as you're suffering less, but bad insofar as you've adjusted to stop caring about a bad thing or thinking of it as something that needs solving - though it's more complicated than this, since suffering less can make you less depressed and being less depressed can put you in a more solution-oriented frame of mind. 5-HT2A receptors are (to vastly oversimplify) the main target of psychedelics. The more strongly it's stimulated, the more active your inference gets. George argues that this means psychedelics are more likely to get you to try to solve your problems. But is this really true? The average person on shrooms doesn't spend their trip contacting HR and reporting their abusive boss, they spend it staring at a flower marveling at how delicate the petals are or something. What problem is this solving? I think Carhart-Harris, Nutt, and maybe George think that this "active coping" isn't necessarily physical action per se, it's rejiggering your world model on a deeper level so that it's more creative and risky in generating strategies. It's a bias towards thinking of problems as solveable. This could potentially fit with the thing where people who do too much LSD become yogis or transhumanists or whatever; they're biased towards believing *all* problems are solveable, even the tough ones like suffering and mortality. (this mostly, but not completely, meshes with Carhart-Harris' other work on psychedelics as relaxed beliefs under uncertainty) All of this was in the paper and my review, but I like the way George ties it together with problems of active inference and the adjusting-predictions vs. changing-the-world tradeoff. If true, this should be testable on the very small scale, with predictions around perception and movement.

Jun 15, 2021 • 28min
Contra Smith On Jewish Selective Immigration
https://astralcodexten.substack.com/p/contra-smith-on-jewish-selective Noah Smith asks whether Jews are really disproportionately successful. (in case it shapes the way you read any of this, both he and I are Jewish) By the numbers, it would seem they are. US Jews have a median household income about 50% higher than US Christians, a net worth about 6x that of Christians, and are about twice as likely as Christians to make more than $100K/year. They're about twice as likely as Christians to get college degrees, and about 15x more likely to win Nobel prizes. These numbers are of about the same magnitude as the gap between blacks and whites, so if you take those numbers seriously, you should probably take these ones seriously too. But Noah wonders if this really needs an interesting explanation, or if it's just a series of boring things on top of each other. He gives five reasons why maybe Jews could do unusually well. I’m going to concentrate on selective immigration, then briefly touch on the others.

Jun 12, 2021 • 30min
Your Book Review: How Children Fail
https://astralcodexten.substack.com/p/your-book-review-how-children-fail [This is the sixteenth of seventeen finalists in the book review contest. It’s not by me - it’s by an ACX reader who will remain anonymous until after voting is done, to prevent their identity from influencing your decisions. This entry was promoted to finalist status by readers; thanks to everyone who voted! - SA] 1: Why are all children so bad at learning in school? Seriously, they’re terrible at it, and nobody ever calls them out as a group. We call out individual children as failing. We call out individual schools and school systems as bad. But the much more dramatic contrast is between learning in school and learning in any other context. In their first five years, kids learn to understand 25,000 words, even if nobody is actively helping them, at the same time as they’re learning most of what they’ll ever know about physics, psychology, and how to pilot a human body. They then struggle to match this vocabulary acquisition rate over their next ten years, despite expert attention, a wealth of resources, personal encouragement, and even prizes.

Jun 11, 2021 • 1h 24min
Your Book Review: Down And Out In Paris And London
[This is the fifteenth of seventeen finalists in the book review contest. It’s not by me - it’s by an ACX reader who will remain anonymous until after voting is done, to prevent their identity from influencing your decisions. This entry was promoted to finalist status by readers; thanks to everyone who voted! - SA] George Orwell’s Down and Out in Paris and London is at least three things; a highly entertaining, almost picaresque tale of rough-and-tumble living in Europe, a serious attempt to catalogue the numerous humiliations and injustices impoverished people were exposed to in Orwell’s time, and a stark comparison between life as a tramp who makes use of robust, if hellish and kafkaesque welfare resources, and as one who tries to get by working terrible jobs and living in disgusting places.

Jun 11, 2021 • 9min
Drug Users Use A Lot Of Drugs
https://astralcodexten.substack.com/p/drug-users-use-a-lot-of-drugs I. If you look at any list of side effects for the FDA-approved version of s-ketamine (Spravato), you see things like urinary tract problems, bladder problems, pain on urination, feeling of urgency to urinate. You can find a bunch of papers like Ketamine: An Important Drug With A Serious Adverse Effect, where they say that ketamine is potentially great for depression, but that the risk of bladder injury needs to be taken really seriously. When I first considered prescribing ketamine, the bladder injury stories scared me so much that I asked a bunch of veteran ketamine prescribers how I should monitor it. They all gave me weird non-commital answers like "I've prescribed ketamine to thousands of patients and never had a problem with this, so I guess don't worry". But why not? There are all these papers saying we should worry, and all these reports in the literature of ketamine-induced bladder injury!

Jun 10, 2021 • 12min
I Will Not Eat The Bugs
https://astralcodexten.substack.com/p/i-will-not-eat-the-bugs From the comments on Moral Costs Of Chicken Vs. Beef: As far as moral concern goes, I think it's right to act your rational conviction, but I can't honestly surmount my own doubt that it makes sense to care about animal well-being...if I really am to say that chickens have moral worth, I don't see any easy spot to get off that train between chickens and insects. Don't worry, you're not getting off the train. The train has already left the station and gotten halfway to Vladivostok. Last month the EU food safety regulator officially approved mealworms as safe for human consumption, sparking a bunch of articles on how bugs are the food of the future (see eg The Guardian: If We Want To Save The Planet, The Future Of Food Is Insects). And although it’s not a massive groundswell of outrage or anything, it’s also sparked a little bit of concern from animal welfare advocates.

Jun 8, 2021 • 7min
Instead Of Pledging To Change The World, Pledge To Change Prediction Markets
https://astralcodexten.substack.com/p/instead-of-pledging-to-change-the In April, Joe Biden pledged to halve US emissions (from their 2005 max) by 2030. This is nice, but I can't help but remember eg Australia's 2009 Copenhagen summit pledge to decrease emissions 5% by 2020 (in fact, they increased 17%). Or Brazil's pledge at the same summit to cut emissions 38% by 2020 (in fact, they increased 45%). Or Canada's pledge for -20% (they got +1%). I'm not cherry-picking bad actors here, I'm just going through the alphabet (pledges source, outcomes source) . For that matter, what about George W. Bush's pledge to return Americans to the moon by 2020? All of these pledges have one thing in common - they expire long after the relevant officials are out of power (and in Biden's case, probably dead). As hard as it is to hold politicians accountable in normal situations, it's even worse here. Sure enough, prediction aggregator Metaculus shows that forecasters only give a 15% chance that we reach Biden's emissions target by 2030. What if instead of pledging anything about emissions, Biden pledged to shift the prediction aggregator? No, seriously, hear me out. Biden pledges that by the end of his term, Metaculus will predict a 51%+ chance that emissions will be less than half their historic maximum by 2030. If Metaculus gives a lower number than this, we can consider Biden to have failed in his pledge, and we can hold it against him when he tries to get re-elected. In order to get Metaculus (or some alternative prediction market) to show a 51% chance of meeting emissions targets, Biden would have to pass a credible package of legislation that puts us on the path to achieving that goal, and makes everyone think it’s more likely than not. Imagine Biden pledges that some prediction market will have a 51% chance of reaching his 2030 emissions target by the time he leaves office. He passes a carbon tax, and the market shoots up from 15% to 30%. Now he knows he’s on the right track, but still has to do more. So he bans a bunch of coal power plants, and it goes up to 45%. He's still not quite there, so he gives big subsidies to solar panels a few days before the campaign season kicks off, the prediction market reaches 51%, and he's able to say he fulfilled his pledge.

Jun 5, 2021 • 23min
Your Book Review: Where's My Flying Car?
https://astralcodexten.substack.com/p/your-book-review-wheres-my-flying [This is the fourteenth of many finalists in the book review contest. It’s not by me - it’s by an ACX reader who will remain anonymous until after voting is done, to prevent their identity from influencing your decisions. I’ll be posting about two of these a week for several months. When you’ve read all of them, I’ll ask you to vote for your favorite, so remember which ones you liked. If you like reading these reviews, check out point 3 here for a way you can help move the contest forward by reading lots more of them - SA] What went wrong in the 1970s? Since then, growth and productivity have slowed, average wages are stagnant, visible progress in the world of "atoms" has practically stopped - the Great Stagnation. About the only thing that has gone well are computers. How is it that we went from the typewriter to the smartphone, but we're still using practically the same cars and airplanes? "Where is my Flying Car?", by J. Storrs Hall, is an attempt to answer that question. His answer is: the Great Stagnation was caused by energy usage flatlining, which was caused by our failure to switch to nuclear energy, which was caused by excessive regulation, which was caused by "green fundamentalism". Three hundred years ago, we burned wood for energy. Then there was coal and the steam engine, which gave us the Industrial Revolution. Then there was oil and gas, giving us cars and airplanes. Then there should have been nuclear fission and nanotech, letting you fit a lifetime's worth of energy in your pocket. Instead, we still drive much the same cars and airplanes, and climate change threatens to boil the Earth.

Jun 4, 2021 • 47min
Your Book Review: The Collapse Of Complex Societies
https://astralcodexten.substack.com/p/your-book-review-the-collapse-of [This is the thirteenth of many finalists in the book review contest. It’s not by me - it’s by an ACX reader who will remain anonymous until after voting is done, to prevent their identity from influencing your decisions. I’ll be posting about two of these a week for several months. When you’ve read all of them, I’ll ask you to vote for your favorite, so remember which ones you liked. If you like reading these reviews, check out point 3 here for a way you can help move the contest forward by reading lots more of them - SA] Joseph Tainter’s explanation for why complex societies collapse in one sentence: the collapse of a society is a response to declining marginal returns on investment in complexity. Tainter uses ‘complexity’ pretty loosely. He’s referring to a broad set of things that include agriculture, fuel extraction, scientific research, education, and sociopolitical complexity. He notes that in any area that produces something good for a society, the lowest-hanging fruit is plucked first, and then value gets harder and harder to extract until there’s little room for improvement. States are the biggest manifestation and driver of social complexity (and I’ll talk mostly about states in the rest of the review) but he’s talking about the abstract property of a society – how large it is, how many specialized social roles it has, how many mechanisms for organizing or doing things. In Tainter’s model, states exist to solve problems. You can think of them as either solving collective social problems, like getting big irrigation systems to work (‘integration theory’), working to placate / oppress the productive populace enough that the elite can keep extracting surplus from them (‘conflict theory’). Either way, states tend to increase in complexity in order to deal with new challenges. That increased complexity imposes greater costs per capita. When the system hits some critical point on the return curve (highest point the graph below), the next stressor makes the state try to unlock the next stage of complexity, which demands more resources than the population can bear. Peasants revolt, republics break away, and the state falls apart.