Book Reviews

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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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.

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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Book review: The End of Alzheimer’s, by Dale E. Bredesen.

Alzheimer’s can be at least postponed for years in most people, and maybe fully cured.

The main catches: It only works if started early enough (and Bredesen only has crude guesses about what’s early enough), the evidence is less rigorous than I’d like, and it’s not a medical treatment, it’s a quantified self approach on steroids ketones.

My guess is that the book is roughly 70% correct. If so, that’s an enormous advance.
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Book review: Seasteading, by Joe Quirk, with Patri Friedman.

Seasteading is an interesting idea. Alas, Quirk’s approach is not quirky enough to do justice to the unusual advantages of seasteading.

The book’s style is too much like a newspaper. Rather than focus on the main advantages of seasteading, it focuses on the concerns of the average person, and on how seasteading might affect them. It quotes interesting people extensively, while being vague about whether the authors are just reporting that those people have ideas, or whether the authors have checked that the ideas are correct. Many of the ideas seem rather fishy.

I suspect that seasteading’s biggest need now is businessmen and/or VCs who can start cruise-ship-sized projects. Yet the book seems aimed more at creating broad, shallow support among ordinary readers than it is at inspiring competent entrepreneurs.
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Book review: Into the Gray Zone: A Neuroscientist Explores the Border Between Life and Death, by Adrian Owen.

Too many books and talks have gratuitous displays of fMRIs and neuroscience. At last, here’s a book where fMRIs are used with fairly good reason, and neuroscience is explained only when that’s appropriate.

Owen provides evidence of near-normal brain activity in a modest fraction of people who had been classified as being in a persistent vegetative state. They are capable of answering yes or no to most questions, and show signs of understanding the plots of movies.

Owen believes this evidence is enough to say they’re conscious. I suspect he’s mostly right about that, and that they do experience much of the brain function that is typically associated with consciousness. Owen doesn’t have any special insights into what we mean by the word consciousness. He mostly just investigates how to distinguish between near-normal mental activity and seriously impaired mental activity.

So what were neurologists previously using to classify people as vegetative? As far as I can tell, they were diagnosing based on a lack of motor responses, even though they were aware of an alternate diagnosis, total locked-in syndrome, with identical symptoms. Locked-in syndrome and persistent vegetative state were both coined (in part) by the same person (but I’m unclear who coined the term total locked-in syndrome).

My guess is that the diagnoses have been influenced by a need for certainty. (whose need? family members? doctors? It’s not obvious).

The book has a bunch of mostly unremarkable comments about ethics. But I was impressed by Owen’s observation that people misjudge whether they’d want to die if they end up in a locked-in state. So how likely is it they’ll mispredict what they’d want in other similar conditions? I should have deduced this from the book stumbling on happiness, but I failed to think about it.

I’m a bit disturbed by Owen’s claim that late-stage Alzheimer’s patients have no sense of self. He doesn’t cite evidence for this conclusion, and his research should hint to him that it would be quite hard to get good evidence on this subject.

Most books written by scientists who made interesting discoveries attribute the author’s success to their competence. This book provides clear evidence for the accidental nature of at least some science. Owen could easily have gotten no signs of consciousness from the first few patients he scanned. Given the effort needed for the scans, I can imagine that that would have resulted in a mistaken consensus of experts that vegetative states were being diagnosed correctly.

Book review: Darwin’s Unfinished Symphony: How Culture Made the Human Mind, by Kevin N. Laland.

This book is a mostly good complement to Henrich’s The Secret of our Success. The two books provide different, but strongly overlapping, perspectives on how cultural transmission of information played a key role in the evolution of human intelligence.

The first half of the book describes the importance of copying behavior in many animals.

I was a bit surprised that animals as simple as fruit flies are able to copy some behaviors of other fruit flies. Laland provides good evidence that a wide variety of species have evolved some ability to copy behavior, and that ability is strongly connected to the benefits of acquiring knowledge from others and the costs of alternative ways of acquiring that knowledge.

Yet I was also surprised that the value of copying is strongly limited by the low reliability with which behavior is copied, except with humans. Laland makes plausible claims that the need for high-fidelity copying of behavior was an important driving force behind the evolution of bigger and more sophisticated brains.

Laland claims that humans have a unique ability to teach, and that teaching is an important adaptation. He means teaching in a much broader sense than we see in schooling – he includes basic stuff that could have preceded language, such as a parent directing a child’s attention to things that the child ought to learn. This seems like a good extension to Henrich’s ideas.

The most interesting chapter theorizes about the origin of human language. Laland’s theory that language evolved for teaching provides maybe a bit stronger selection pressure than other theories, but he doesn’t provide much reason to reject competing theories.

Laland presents seven criteria for a good explanation of the evolution of language. But these criteria look somewhat biased toward his theory.

Laland’s first two criteria are that language should have been initially honest and cooperative. He implies that it must have been more honest and cooperative than modern language use is, but he isn’t as clear about that as I would like. Those two criteria seem designed as arguments against the theory that language evolved to impress potential mates. The mate-selection theory involves plenty of competition, and presumably a fair amount of deception. But better communicators do convey important evidence about the quality of their genes, even if they’re engaging in some deception. That seems sufficient to drive the evolution of language via mate-selection pressures.

Laland’s theory seems to provide a somewhat better explanation of when language evolved than most other theories do, so I’m inclined to treat it as one of the top theories. But I don’t expect any consensus on this topic anytime soon.

The book’s final four chapters seemed much less interesting. I recommend skipping them.

Henrich’s book emphasized evidence that humans are pretty similar to other apes. Laland emphasizes ways in which humans are unique (language and teaching ability). I didn’t notice any cases where they directly contradicted each other, but it’s a bit disturbing that they left quite different impressions while saying mostly appropriate things.

Henrich claimed that increasing climate variability created increased rewards for the fast adaptation that culture enabled. Laland disagrees, saying that cultural change itself is a more plausible explanation for the kind of environmental change that incentivized faster adaptation. My intuition says that Laland’s conclusion is correct, but he seems a bit overconfident about it.

Overall, Laland’s book is less comprehensive and less impressive than Henrich’s book, but is still good enough to be in my top ten list of books on the evolution of intelligence.

Update on 2017-08-18: I just read another theory about the evolution of language which directly contradicts Laland’s claim that early language needed to be honest and cooperative. Wild Voices: Mimicry, Reversal, Metaphor, and the Emergence of Language claims that an important role of initial human vocal flexibility was to deceive other species.