Book review: Surfing Uncertainty: Prediction, Action, and the Embodied Mind, by Andy Clark.

Surfing Uncertainty describes minds as hierarchies of prediction engines. Most behavior involves interactions between a stream of information that uses low-level sensory data to adjust higher level predictive models of the world, and another stream of data coming from high-level models that guides low-level sensory processes to better guess the most likely interpretations of ambiguous sensory evidence.

Clark calls this a predictive processing (PP) model; others refer to is as predictive coding.

The book is full of good ideas, presented in a style that sapped my curiosity.

Jeff Hawkins has a more eloquent book about PP (On Intelligence), which focuses on how PP might be used to create artificial intelligence. The underwhelming progress of the company Hawkins started to capitalize on these ideas suggests it wasn’t the breakthrough that AI researchers were groping for. In contrast, Clark focuses on how PP helps us understand existing minds.

The PP model clearly has some value. The book was a bit more thorough than I wanted at demonstrating that. Since I didn’t find that particularly new or surprising, I’ll focus most of this review on a few loose threads that the book left dangling. So don’t treat this as a summary of the book (see Slate Star Codex if you want that, or if my review is too cryptic to understand), but rather as an exploration of the questions that the book provoked me to think about.

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Book review: The Elephant in the Brain, by Kevin Simler and Robin Hanson.

This book is a well-written analysis of human self-deception.

Only small parts of this book will seem new to long-time readers of Overcoming Bias. It’s written more to bring those ideas to a wider audience.

Large parts of the book will seem obvious to cynics, but few cynics have attempted to explain the breadth of patterns that this book does. Most cynics focus on complaints about some group of people having worse motives than the rest of us. This book sends a message that’s much closer to “We have met the enemy, and he is us.”

The authors claim to be neutrally describing how the world works (“We aren’t trying to put our species down or rub people’s noses in their own shortcomings.”; “… we need this book to be a judgment-free zone”). It’s less judgmental than the average book that I read, but it’s hardly neutral. The authors are criticizing, in the sense that they’re rubbing our noses in evidence that humans are less virtuous than many people claim humans are. Darwin unavoidably put our species down in the sense of discrediting beliefs that we were made in God’s image. This book continues in a similar vein.

This suggests the authors haven’t quite resolved the conflict between their dreams of upholding the highest ideals of science (pursuit of pure knowledge for its own sake) and their desire to solve real-world problems.

The book needs to be (and mostly is) non-judgmental about our actual motives, in order to maximize our comfort with acknowledging those motives. The book is appropriately judgmental about people who pretend to have more noble motives than they actually have.

The authors do a moderately good job of admitting to their own elephants, but I get the sense that they’re still pretty hesitant about doing so.

Impact

Most people will underestimate the effects which the book describes.
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Book review: Warnings: Finding Cassandras to Stop Catastrophes, by Richard A. Clarke and R.P. Eddy.

This book is moderately addictive softcore version of outrage porn. Only small portions of the book attempt to describe how to recognize valuable warnings and ignore the rest. Large parts of the book seem written mainly to tell us which of the people portrayed in the book we should be outraged at, and which we should praise.

Normally I wouldn’t get around to finishing and reviewing a book containing this little information value, but this one was entertaining enough that I couldn’t stop.

The authors show above-average competence at selecting which warnings to investigate, but don’t convince me that they articulated how they accomplished that.

I’ll start with warnings on which I have the most expertise. I’ll focus a majority of my review on their advice for deciding which warnings matter, even though that may give the false impression that much of the book is about such advice.
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I’ve donated/sold more than 80% of my cryptocurrency holdings (Ripple and Bitcoin) over the past two weeks, after holding them without trading for around 4 years.

When I last blogged about Bitcoin, I said I would buy Bitcoin soon. That plan failed because I didn’t manage to convince the appropriate company that I’d documented my identity, so I didn’t find a way to transfer money from a bank to an account from which I could buy Bitcoin. (Difficulties like that were one reason why cryptocurrencies used to be priced too low). I procrastinated for two years, then found a convenient opportunity when MIRI needed to unload some Ripple.

My guess is that the leading cryptocurrencies will be somewhat higher a decade or two from now, but the prospects over the next year or two seem fairly poor compared to the risks.

Much of my expected value for the cryptocurrencies used to come from a 2+% chance of a hundred-fold rise. But a hundred-fold rise from current levels seems a bit less than 1% likely.

I compare cryptocurrency trends mainly to the gold bubble of 1980, since gold is primarily a store of value that pays no income, and is occasionally used as a currency.

I made some money once before by predicting that an unusual market pattern would repeat, with the same seasonal timing. So I’ve been guessing that cryptocurrencies would peak in mid-January. Yes, that’s pretty weak evidence, but weak evidence is all I expect to get.

I’ve also tried to extract some evidence from price trends. That usually provides only a tiny benefit in normal markets, but I suspect I get some value in high-volume inefficient markets (mainly ones where it’s hard to short) by detecting how eager traders are to buy and sell.

I watched the markets nervously in December, thinking that a significant bubble was developing, but seeing signs that any peak was still at least weeks in the future. Then I got nervous enough on January 2 to donate some Ripple to CFAR, even though I still saw signs that the market hadn’t peaked.

By January 5, I stopped seeing signs that the trend was still up, but I waited several days before reacting, hoping for rebounds that ended up being weaker than I expected. I ended up selling at a lower average price than CFAR got for what I donated to them, because dissatisfaction with the lower-than-recent price made me hesitant to sell.

An important lesson to draw from this is to always try to sell financial assets before the peak. Endowment effect is hard to avoid.

P.S. – It’s unclear whether cryptocurrencies are important enough to influence other stores of value. My best guess is that gold would be 5 to 10% higher today if it weren’t for cryptocurrencies. And the recent rise in cryptocurrencies coincides with a rise in expected inflation, but that’s more likely to be a coincidence, than due to people abandoning dollars because they see cryptocurrencies as a better store of value.

Book review: Feeding Everyone No Matter What: Managing Food Security After Global Catastrophe, by David Denkenberger and Joshua M. Pearce.

I have very mixed feelings about this book.

It discusses some moderately unlikely risks – scenarios where most crops fail worldwide for several years, due to inadequate sunlight.

It’s hard to feel emotionally satisfied about a tolerable but uncomfortable response to disasters, when ideally we’d prevent those disasters in the first place. And the disasters seem sufficiently improbable that I don’t feel comfortable thinking frequently about them. But we don’t yet have a foolproof way of preventing catastrophic climate changes, and there are things we can do to survive them. So logic tells me that we ought to devote a few resources to preparing.

The authors sketch a set of strategies which could conceivably ensure that nobody starves (Wikipedia has a good summary). There might even be a bit of room for mistakes, but not much.

The book focuses on the technical problems, with the hope that others will solve the political problems. This makes some sense, as the feasibility of various political solutions is very different if the best political strategy saves 95% of people than if it saves 30%.

It’s a bit disturbing that this seems to be the most expert analysis available for these scenarios – the authors appear fairly competent, but seem to have done less research than I expect from a technical book. They may have made the right choice to publish early, in order to attract more support. I’m mainly disturbed by what the lack of expertise says about societal competence.

The book leaves me with lots of uncertainty about how hard it is to improve on the meager preparations that have been done so far.

For example, I expect there are a moderate number of people who know something about rapidly scaling up mushroom production. Are they already capable of handling the needed changes? Or are drastically different preparations needed? It’s hard for me to tell without developing significant expertise in growing mushrooms.

There’s probably an urgent need for a bit more preparation for extracting nutrition from ordinary leaves. In particular, I expect it to matter what kinds of leaves to use. The book mostly talks of leaves from trees, but careless people in my area might include poison hemlock leaves, with disastrous results. A small amount of advance preparation should be able to cause large reductions in this kind of mistake.

Another simple preparation that’s needed is a better awareness of where to look in a crisis. The news media in particular ought to be able to quickly find this kind of information even when they’re overwhelmed with problems.

I’m guessing that a few hundred thousand dollars of additional effort in this area would have high expected value, with strongly diminishing returns after that. I’ve donated a small amount to ALLFED, and I encourage you to donate a little bit as well.

I got interested in trying ashwagandha due to The End of Alzheimer’s. That book also caused me to wonder whether I should optimize my thyroid hormone levels. And one of the many features of ashwagandha is that it improves thyroid levels, at least in hypothyroid people – I found conflicting reports about what it does to hyperthyroid people.

I had plenty of evidence that my thyroid levels were lower than optimal, e.g. TSH levels measured at 2.58 in 2012, 4.69 in 2013, and 4.09 this fall [1]. And since starting alternate day calorie restriction, I saw increasing hypothyroid symptoms: on calorie restriction days my feet felt much colder around bedtime, my pulse probably slowed a bit, my body burned fewer calories, and I got vague impressions of having less energy. Presumably my body was lowering my thyroid levels to keep my weight from dropping.

I researched the standard treatments for hypothyroidism, but was discouraged by the extent of disagreement among doctors about the wisdom of treating hypothyroidism when it’s as mild as mine was. It seems like mainstream medical opinion says the risks slightly outweigh the rewards, and a sizable minority of doctors, relying on more subjective evidence, say the rewards are large, and don’t say much about the risks. Plus, the evidence for optimal thyroid levels protecting against Alzheimer’s seems to come mainly from correlations that are seen only in women.

Also, the standard treatments for hypothyroidism require a prescription (probably for somewhat good reasons), which may have deterred me by more than a rational amount.

So I decided to procrastinate any attempt to optimize my thyroid hormones, and since I planned to try ashwagandha and DHEA for other reasons, I hoped to get some evidence from the small increases to thyroid hormones that I expected from those two supplements.

I decided to try ashwagandha first, due mainly to the large number of problems it may improve – anxiety, inflammation, stress, telomeres, cholesterol, etc.
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[Warning: long post, of uncertain value, with annoyingly uncertain conclusions.]

This post will focus on how hardware (cpu power) will affect AGI timelines. I will undoubtedly overlook some important considerations; this is just a model of some important effects that I understand how to analyze.

I’ll make some effort to approach this as if I were thinking about AGI timelines for the first time, and focusing on strategies that I use in other domains.

I’m something like 60% confident that the most important factor in the speed of AI takeoff will be the availability of computing power.

I’ll focus here on the time to human-level AGI, but I suspect this reasoning implies getting from there to superintelligence at speeds that Bostrom would classify as slow or moderate.
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Book review: Inadequate Equilibria, by Eliezer Yudkowsky.

This book (actually halfway between a book and a series of blog posts) attacks the goal of epistemic modesty, which I’ll loosely summarize as reluctance to believe that one knows better than the average person.

1.

The book starts by focusing on the base rate for high-status institutions having harmful incentive structures, charting a middle ground between the excessive respect for those institutions that we see in mainstream sources, and the cynicism of most outsiders.

There’s a weak sense in which this is arrogant, namely that if were obvious to the average voter how to improve on these problems, then I’d expect the problems to be fixed. So people who claim to detect such problems ought to have decent evidence that they’re above average in the relevant skills. There are plenty of people who can rationally decide that applies to them. (Eliezer doubts that advising the rest to be modest will help; I suspect there are useful approaches to instilling modesty in people who should be more modest, but it’s not easy). Also, below-average people rarely seem to be attracted to Eliezer’s writings.

Later parts of the book focus on more personal choices, such as choosing a career.

Some parts of the book seem designed to show off Eliezer’s lack of need for modesty – sometimes successfully, sometimes leaving me suspecting he should be more modest (usually in ways that are somewhat orthogonal to his main points; i.e. his complaints about “reference class tennis” suggest overconfidence in his understanding of his debate opponents).

2.

Eliezer goes a bit overboard in attacking the outside view. He starts with legitimate complaints about people misusing it to justify rejecting theory and adopt “blind empiricism” (a mistake that I’ve occasionally made). But he partly rejects the advice that Tetlock gives in Superforecasting. I’m pretty sure Tetlock knows more about this domain than Eliezer does.

E.g. Eliezer says “But in novel situations where causal mechanisms differ, the outside view fails—there may not be relevantly similar cases, or it may be ambiguous which similar-looking cases are the right ones to look at.”, but Tetlock says ‘Nothing is 100% “unique” … So superforecasters conduct creative searches for comparison classes even for seemingly unique events’.

Compare Eliezer’s “But in many contexts, the outside view simply can’t compete with a good theory” with Tetlock’s commandment number 3 (“Strike the right balance between inside and outside views”). Eliezer seems to treat the approaches as antagonistic, whereas Tetlock advises us to find a synthesis in which the approaches cooperate.

3.

Eliezer provides a decent outline of what causes excess modesty. He classifies the two main failure modes as anxious underconfidence, and status regulation. Anxious underconfidence definitely sounds like something I’ve felt somewhat often, and status regulation seems pretty plausible, but harder for me to detect.

Eliezer presents a clear model of why status regulation exists, but his explanation for anxious underconfidence doesn’t seem complete. Here are some of my ideas about possible causes of anxious underconfidence:

  • People evaluate mistaken career choices and social rejection as if they meant death (which was roughly true until quite recently), so extreme risk aversion made sense;
  • Inaction (or choosing the default action) minimizes blame. If I carefully consider an option, my choice says more about my future actions than if I neglect to think about the option;
  • People often evaluate their success at life by counting the number of correct and incorrect decisions, rather than adding up the value produced;
  • People who don’t grok the Bayesian meaning of the word “evidence” are likely to privilege the scientific and legal meanings of evidence. So beliefs based on more subjective evidence get treated as second class citizens.

I suspect that most harm from excess modesty (and also arrogance) happens in evolutionarily novel contexts. Decisions such as creating a business plan for a startup, or writing a novel that sells a million copies, are sufficiently different from what we evolved to do that we should expect over/underconfidence to cause more harm.

4.

Another way to summarize the book would be: don’t aim to overcompensate for overconfidence; instead, aim to eliminate the causes of overconfidence.

This book will be moderately popular among Eliezer’s fans, but it seems unlikely to greatly expand his influence.

It didn’t convince me that epistemic modesty is generally harmful, but it does provide clues to identifying significant domains in which epistemic modesty causes important harm.

Book review: The Causes of War and the Spread of Peace: But Will War Rebound?, by Azar Gat.

This book provides a good synthesis of the best ideas about why wars happen.

It overlaps a good deal with Pinker’s The Better Angels of Our Nature. Pinker provides much more detailed evidence, but Gat has a much better understanding than Pinker of the theories behind the trends.
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