Science and Technology

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.

Book review: The Hungry Brain: Outsmarting the Instincts That Make Us Overeat, by Stephan Guyenet.

Researchers who studied obesity in rats used to have trouble coaxing their rats to overeat. The obvious approaches (a high fat diet, or a high sugar diet) were annoyingly slow. Then they stumbled on the approach of feeding human junk food to the rats, and made much faster progress.

What makes something “junk food”? The best parts of this book help to answer this, although some ambiguity remains. It mostly boils down to palatability (is it yummier than what our ancestors evolved to expect? If so, it’s somewhat addictive) and caloric density.

Presumably designers of popular snack foods have more sophisticated explanations of what makes people obese, since that’s apparently identical to what they’re paid to optimize (with maybe a few exceptions, such as snacks that are marketed as healthy or ethical). Yet researchers who officially study obesity seem reluctant to learn from snack food experts. (Because they’re the enemy? Because they’re low status? Because they work for evil corporations? Your guess is likely as good as mine.)

Guyenet provides fairly convincing evidence that it’s simple to achieve a healthy weight while feeling full. (E.g. the 20 potatoes a day diet). To the extent that we need willpower, it’s to avoid buying convenient/addictive food, and to avoid restaurants.

My experience is that I need a moderate amount of willpower to follow Guyenet’s diet ideas, and that it would require large amount of willpower if I attended many social events involving food. But for full control over my weight, it seemed like I needed to supplement a decent diet with some form of intermittent fasting (e.g. alternate day calorie restriction); Guyenet says little about that.

Guyenet’s practical advice boils down to a few simple rules: eat whole foods that resemble what our ancestors ate; don’t have other “food” anywhere that you can quickly grab it; sleep well; exercise; avoid stress. That’s sufficiently similar to advice I’ve heard before that I’m confident The Hungry Brain won’t revolutionize many people’s understanding of obesity. But it’s got a pretty good ratio of wisdom to questionable advice, and I’m unaware of reasons to expect much more than that.

Guyenet talks a lot about neuroscience. That would make sense if readers wanted to learn how to fix obesity via brain surgery. The book suggests that, in the absence of ethical constraints, it might be relatively easy to cure obesity by brain surgery. Yet I doubt such a solution would become popular, even given optimistic assumptions about safety.

An alternate explanation is that Guyenet is showing off his knowledge of brains, in order to show that he’s smart enough to have trustworthy beliefs about diets. But that effect is likely small, due to competition among diet-mongers for comparable displays of smartness.

Or maybe he’s trying to combat dualism, in order to ridicule the “just use willpower” approach to diet? Whatever the reason is, the focus on neuroscience implies something unimpressive about the target audience.

You should read this book if you eat a fairly healthy diet but are still overweight. Otherwise, read Guyenet’s blog instead, for a wider variety of health advice.

The paper When Will AI Exceed Human Performance? Evidence from AI Experts reports ML researchers expect AI will create a 5% chance of “Extremely bad (e.g. human extinction)” consequences, yet they’re quite divided over whether that implies it’s an important problem to work on.

Slate Star Codex expresses confusion about and/or disapproval of (a slightly different manifestation of) this apparent paradox. It’s a pretty clear sign that something is suboptimal.

Here are some conjectures (not designed to be at all mutually exclusive).
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Book review: Daring Greatly: How the Courage to Be Vulnerable Transforms the Way We Live, Love, Parent, and Lead, by Brene Brown.

I almost didn’t read this because I was unimpressed by the TEDx video version of it, but parts of the book were pretty good (mainly chapters 3 and 4).

The book helped clarify my understanding of shame: how it differs from guilt, how it often constrains us without accomplishing anything useful, and how to reduce it.

She emphasizes that we can reduce shame by writing down or talking about shameful thoughts. She doesn’t give a strong explanation of what would cause that effect, but she prompted me to generate one: parts of my subconscious mind initially want to hide the shameful thoughts, and that causes them to fight the parts of my mind that want to generate interesting ideas. The act of communicating those ideas to the outside world convinces those censor-like parts of my mind to worry less about the ideas (because it’s too late? or because the social response is evidence that the censor was mistakenly worried? I don’t know).

I was a bit confused by her use of the phrase “scarcity culture”. I was initially tempted to imagine she wanted us to take a Panglossian view in which we ignore the resource constraints that keep us from eliminating poverty. But the context suggests she’s thinking more along the lines of “a culture of envy”. Or maybe a combination of perfectionism plus status seeking? Her related phrase “never enough” makes sense if I interpret it as “never impressive enough”.

I find it hard to distinguish those “bad” attitudes from the attitudes that seem important for me to strive for self-improvement.

She attempts to explain that distinction in a section on perfectionism. She compares perfectionism to healthy striving by noting that perfectionism focuses on what other people will think of us, whereas healthy striving is self-focused. Yet I’m pretty sure I’ve managed to hurt myself with perfectionism while focusing mostly on worries about how I’ll judge myself.

I suspect that healthy striving requires more focus on the benefits of success, and less attention to fear of failure, than is typical of perfectionism. The book hints at this, but doesn’t say it clearly when talking about perfectionism. Maybe she describes perfectionism better in her book The Gifts of Imperfection. Should I read that?

Her claim “When we stop caring about what people think, we lose our capacity for connection” feels important, and an area where I have trouble.

The book devotes too much attention to gender-stereotypical problems with shame. Those stereotypes are starting to look outdated. And it shouldn’t require two whole chapters to say that advice on how to have healthy interactions with people should also apply to relations at work, and to relations between parents and children.

The book was fairly easy to read, and parts of it are worth rereading.

A new paper titled When Will AI Exceed Human Performance? Evidence from AI Experts reports some bizarre results. From the abstract:

Researchers believe there is a 50% chance of AI outperforming humans in all tasks in 45 years and of automating all human jobs in 120 years, with Asian respondents expecting these dates much sooner than North Americans.

So we should expect a 75 year period in which machines can perform all tasks better and more cheaply than humans, but can’t automate all occupations. Huh?

I suppose there are occupations that consist mostly of having status rather than doing tasks (queen of England, or waiter at a classy restaurant that won’t automate service due to the high status of serving food the expensive way). Or occupations protected by law, such as gas station attendants who pump gas in New Jersey, decades after most drivers switched to pumping for themselves.

But I’d be rather surprised if machine learning researchers would think of those points when answering a survey in connection with a machine learning conference.

Maybe the actual wording of the survey questions caused a difference that got lost in the abstract? Hmmm …

“High-level machine intelligence” (HLMI) is achieved when unaided machines can accomplish every task better and more cheaply than human workers


when all occupations are fully automatable. That is, when for any occupation, machines could be built to carry out the task better and more cheaply than human workers.

I tried to convince myself that the second version got interpreted as referring to actually replacing humans, while the first version referred to merely being qualified to replace humans. But the more I compared the two, the more that felt like wishful thinking. If anything, the “unaided” in the first version should make that version look farther in the future.

Can I find any other discrepancies between the abstract and the details? The 120 years in the abstract turns into 122 years in the body of the paper. So the authors seem to be downplaying the weirdness of the results.

There’s even a prediction of a 50% chance that the occupation “AI researcher” will be automated in about 88 years (I’m reading that from figure 2; I don’t see an explicit number for it). I suspect some respondents said this would take longer than for machines to “accomplish every task better and more cheaply”, but I don’t see data in the paper to confirm that [1].

A more likely hypothesis is that researchers alter their answers based on what they think people want to hear. Researchers might want to convince their funders that AI deals with problems that can be solved within the career of the researcher [2], while also wanting to reassure voters that AI won’t create massive unemployment until the current generation of workers has retired.

That would explain the general pattern of results, although the magnitude of the effect still seems strange. And it would imply that most machine learning researchers are liars, or have so little understanding of when HLMI will arrive that they don’t notice a 50% shift in their time estimates.

The ambiguity in terms such as “tasks” and “better” could conceivably explain confusion over the meaning of HLMI. I keep intending to write a blog post that would clarify concepts such as human-level AI and superintelligence, but then procrastinating because my thoughts on those topics are unclear.

It’s hard to avoid the conclusion that I should reduce my confidence in any prediction of when AI will reach human-level competence. My prior 90% confidence interval was something like 10 to 300 years. I guess I’ll broaden it to maybe 8 to 400 years [3].

P.S. – See also Katja’s comments on prior surveys.

[1] – the paper says most participants were asked the question that produced the estimate of 45 years to HLMI, the rest got the question that produced the 122 year estimate. So the median for all participants ought to be less than about 84 years, unless there are some unusual quirks in the data.

[2] – but then why do experienced researchers say human-level AI is farther in the future than new researchers, who presumably will be around longer? Maybe the new researchers are chasing fads or get-rich-quick schemes, and will mostly quit before becoming senior researchers?

[3] – years of subjective time as experienced by the fastest ems. So probably nowhere near 400 calendar years.

Book review: The Measure of All Minds: Evaluating Natural and Artificial Intelligence, by José Hernández-Orallo.

Much of this book consists of surveys of the psychometric literature. But the best parts of the book involve original results that bring more rigor and generality to the field. The best parts of the book approach the quality that I saw in Judea Pearl’s Causality, and E.T. Jaynes’ Probability Theory, but Measure of All Minds achieves a smaller fraction of its author’s ambitions, and is sometimes poorly focused.

Hernández-Orallo has an impressive ambition: measure intelligence for any agent. The book mentions a wide variety of agents, such as normal humans, infants, deaf-blind humans, human teams, dogs, bacteria, Q-learning algorithms, etc.

The book is aimed at a narrow and fairly unusual target audience. Much of it reads like it’s directed at psychology researchers, but the more original parts of the book require thinking like a mathematician.

The survey part seems pretty comprehensive, but I wasn’t satisfied with his ability to distinguish the valuable parts (although he did a good job of ignoring the politicized rants that plague many discussions of this subject).

For nearly the first 200 pages of the book, I was mostly wondering whether the book would address anything important enough for me to want to read to the end. Then I reached an impressive part: a description of an objective IQ-like measure. Hernández-Orallo offers a test (called the C-test) which:

  • measures a well-defined concept: sequential inductive inference,
  • defines the correct responses using an objective rule (based on Kolmogorov complexity),
  • with essentially no arbitrary cultural bias (the main feature that looks like an arbitrary cultural bias is the choice of alphabet and its order)[1],
  • and gives results in objective units (based on Levin’s Kt).

Yet just when I got my hopes up for a major improvement in real-world IQ testing, he points out that what the C-test measures is too narrow to be called intelligence: there’s a 960 line Perl program that exhibits human-level performance on this kind of test, without resembling a breakthrough in AI.
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I’ve recently noticed some possibly important confusion about machine learning (ML)/deep learning. I’m quite uncertain how much harm the confusion will cause.

On MIRI’s Intelligent Agent Foundations Forum:

If you don’t do cognitive reductions, you will put your confusion in boxes and hide the actual problem. … E.g. if neural networks are used to predict math, then the confusion about how to do logical uncertainty is placed in the black box of “what this neural net learns to do”

On SlateStarCodex:

Imagine a future inmate asking why he was denied parole, and the answer being “nobody knows and it’s impossible to find out even in principle” … (DeepMind employs a Go master to help explain AlphaGo’s decisions back to its own programmers, which is probably a metaphor for something)

A possibly related confusion, from a conversation that I observed recently: philosophers have tried to understand how concepts work for centuries, but have made little progress; therefore deep learning isn’t very close to human-level AGI.

I’m unsure whether any of the claims I’m criticizing reflect actually mistaken beliefs, or whether they’re just communicated carelessly. I’m confident that at least some people at MIRI are wise enough to avoid this confusion [1]. I’ve omitted some ensuing clarifications from my description of the deep learning conversation – maybe if I remembered those sufficiently well, I’d see that I was reacting to a straw man of that discussion. But it seems likely that some people were misled by at least the SlateStarCodex comment.

There’s an important truth that people refer to when they say that neural nets (and machine learning techniques in general) are opaque. But that truth gets seriously obscured when rephrased as “black box” or “impossible to find out even in principle”.
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Book review: The Rationality Quotient: Toward a Test of Rational Thinking, by Keith E. Stanovich, Richard F. West and Maggie E. Toplak.

This book describes an important approach to measuring individual rationality: an RQ test that loosely resembles an IQ test. But it pays inadequate attention to the most important problems with tests of rationality.


My biggest concern about rationality testing is what happens when people anticipate the test and are motivated to maximize their scores (as is the case with IQ tests). Do they:

  • learn to score high by “cheating” (i.e. learn what answers the test wants, without learning to apply that knowledge outside of the test)?
  • learn to score high by becoming more rational?
  • not change their score much, because they’re already motivated to do as well as their aptitudes allow (as is mostly the case with IQ tests)?

Alas, the book treats these issues as an afterthought. Their test knowingly uses questions for which cheating would be straightforward, such as asking whether the test subject believes in science, and whether they prefer to get $85 now rather than $100 in three months. (If they could use real money, that would drastically reduce my concerns about cheating. I’m almost tempted to advocate doing that, but doing so would hinder widespread adoption of the test, even if using real money added enough value to pay for itself.)

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Two and a half years ago, Eliezer was (somewhat plausibly) complaining that virtually nobody outside of MIRI was working on AI-related existential risks.

This year (at EAGlobal) one of MIRI’s talks was a bit hard to distinguish from an AI safety talk given by someone with pretty mainstream AI affiliations.

What happened in that time to cause that shift?

A large change was catalyzed by the publication of Superintelligence. I’ve been mildly disappointed about how little it affected discussions among people who were already interested in the topic. But Superintelligence caused a large change in how many people are willing to express concern over AI risks. That’s presumably because Superintelligence looks sufficiently academic and neutral to make many people comfortable about citing it, whereas similar arguments by Eliezer/MIRI didn’t look sufficiently prestigious within academia.

A smaller part of the change was MIRI shifting its focus somewhat to be more in line with how mainstream machine learning (ML) researchers expect AI to reach human levels.

Also, OpenAI has been quietly shifting in a more MIRI-like direction (I’m very unclear on how big a change this is). (Paul Christiano seems to deserve some credit for both the MIRI and OpenAI shifts in strategies.)

Given those changes, it seems like MIRI ought to be able to attract more donations than before. Especially since it has demonstrated evidence of increasing competence, and also because HPMoR seemed to draw significantly more people into the community of people who are interested in MIRI.

MIRI has gotten one big grant from OpenPhilanthropy that it probably couldn’t have gotten when mainstream AI researchers were treating MIRI’s concerns as too far-fetched to be worth commenting on. But donations from MIRI’s usual sources have stagnated.

That pattern suggests that MIRI was previously benefiting from a polarization effect, where the perception of two distinct “tribes” (those who care about AI risks versus those who promote AI) energized people to care about “their tribe”.

Whereas now there’s no clear dividing line between MIRI and mainstream researchers. Also, there’s lots of money going into other organizations that plan to do something about AI safety. (Most of those haven’t yet articulated enough of a strategy to make me optimistic that that money is well spent. I still endorse the ideas I mentioned last year in How much Diversity of AGI-Risk Organizations is Optimal?. I’m unclear on how much diversity of approaches we’re getting from the recent proliferation of AI safety organizations.)

That kind of pattern of donations creates perverse incentives to charities to at least market themselves as fighting a powerful group of people, rather than (as the ideal charity should be) addressing a neglected problem. Even if that marketing doesn’t distort a charity’s operations, the charity will be tempted to use counterproductive alarmism. AI risk organizations have resisted those temptations (at least recently), but it seems risky to tempt them.

That’s part of why I recently made a modest donation to MIRI, in spite of the uncertainty over the value of their efforts (I had last donated to them in 2009).