Bayesian Investor Blog

Book review: Monkeyluv: And Other Essays on Our Lives as Animals by Robert M. Sapolsky.
This collection of essays starts out by rehashing nature/nurture arguments that ought to be widely understood by now, but then becomes mostly entertaining and occasionally quite informative.
He mentions one interesting study which questions sexual selection arguments put forward by Geoffrey Miller and others about animals selecting mates with better genes. The study shows that female Mallards produce stronger offspring after mating with more attractive males because they invest more resources in those eggs, rather than because of anything that seems connected to the genes provided by the males.
He helps explain the attraction of gambling by describing experiments which show larger dopamine releases due to rewards that are most uncertain (the subject thinks they have a 50% chance of happening) than is released when there’s more certainty (e.g. either a 25% chance or a 75% chance) of the same reward.
One place where I was disappointed was when he described “repressive personalities”, which he made seem quite similar to Aspergers, and made me wonder whether I fit his description. “dislike novelty”? My reaction to novelty is sufficiently context-dependent that any answer is plausible. “prefer structure and predictability”? Yes and usually. “poor at expressing emotions or at reading the nuances of emotions in other people”? That’s me. “can tell you what they’re having for dinner two weeks from Thursday”? I could probably predict 5 days in advance with 50% accuracy, so I’m probably closer than most people. So I Googled and found another description (mentioning the same researcher that Sapolsky mentioned) in the Sciences and find descriptions of “repressive personality” that seem wildly different from me (”a strong personal need for social conformity” and “agreement with statements framed as absolutes, statements loaded with the words never and always”). Who wrote this competing description? Wait, it’s the same Sapolsky! It looks like his current description reuses a small piece of an older article with inadequate thought to whether it’s complete enough.

Book review: Why Humans Cooperate: A Cultural and Evolutionary Explanation by Joseph Henrich, Natalie Henrich.
This book provides a clear and informative summary of the evolutionary theories that explain why people cooperate (but few novel ideas), and some good but unexciting evidence that provides a bit of support for the theories.
One nice point they make is that unconditional altruism discourages cooperation - it’s important to have some sort of reciprocity (possibly indirect) for a society to prevent non-cooperators from outcompeting cooperators.
The one surprising fact uncovered in their field studies is that people are more generous in the Dictator Game than in the Ultimatum Game (games where one player decides how to divide money between himself and another player; in the Ultimatum Game the second player can reject the division, in which case neither gets anything). It appears that the Ultimatum Game encourages people to think in terms of business-like interactions, but in the Dictator Game a noncompetitive mode of thought dominates.

I have long been dissatisfied with the attempts I’ve seen to explain why evolution hasn’t made homosexuality rare.
A new paper in PLoS ONE: Sexually Antagonistic Selection in Human Male Homosexuality presents a model that seems adequate.
The main idea (from this summary) is that

a heightened sexual response to men could make women more likely to pass on their genes, while making men possessing the trait less likely to do so.

The paper notes this evidence to support it:

homosexuals’ mothers are more fecund than mothers of heterosexuals. Further female fecundity asymmetries include a higher fecundity of maternal vs. paternal aunts of homosexuals

This model provides hints about why homosexuality is not rare among other species.
My main reservation is that the model leads me to expect bisexuality to be somewhat more likely than homosexuality.

Book review: Seeing Red: A Study in Consciousness (Mind/Brain/Behavior Initiative) by Nicholas Humphrey,
This book provides a clear and simple description of phenomena that are often described as qualia, and a good guess about how and why they might have evolved as convenient ways for one part of a brain to get useful information from other parts. It uses examples of blindsight to clarify the difference between using sensory input and being aware of that input.
I liked the description of consciousness as being “temporally thick” rather than being about an instantaneous “now”, suggesting that it includes pieces of short-term memory and possibly predictions about the next few seconds.
The book won’t stop people from claiming that there’s still something mysterious about qualia, but it will make it hard for them to claim that they have a well-posed question that hasn’t been answered. It avoids most debates over meanings of words by usually sticking to simpler and less controversial words than qualia, and only using the word consciousness in ways that are relatively uncontroversial.
The book is short and readable, yet the important parts of it are concise enough that it could be adequately expressed in a shorter essay.

Book review: The First Word: The Search for the Origins of Language by Christine Kenneally
This book contains a few good ideas, but spends more time than I want discussing the personalities and politics that have been involved in the field.
It presents some good arguments against the “big bang” theory of the origin of human language (which suggests that one mutation may have created syntactic abilities that don’t correspond to anything in other species), mainly by presenting evidence that human language is not a monolithic feature, and that most aspects of it resemble features which can be seen in other species. For example, some of our syntactic ability involves reusing parts of the brain that provide motor control.
I’m uncertain whether the “big bang” theory she argues against is actually believed by any serious scholar, because those who may have advocated it haven’t articulated much of a theory (partly because they think there’s too little evidence to say much about the origin of language).
The most valuable idea I got from the book was the possibility that the development of human language may have been a byproduct of a sophisticated theory of mind. Other apes seem to get less benefit from communications because with only the limited theory of mind that a typical chimp has, there’s little that improved communication by one individual can do to increase cooperation between individuals.

Book review: The Robot’s Rebellion: Finding Meaning in the Age of Darwin by Keith E. Stanovich.
This book asks us to notice the conflicts between the goals our genes created us to serve and the goals that we as individuals benefit from achieving. Its viewpoint is somewhat new and unique. Little of the substance of the book seemed new, but there were a number of places where the book provides better ways of communicating ideas than I had previously seen.
The title led me to hope that the book would present a very ambitious vision of how we might completely free ourselves from genes and Darwinian evolution, but his advice focuses on modest nearer term benefits we can get from knowledge produced by studying heuristics and biases. The advice consists mainly of elaborations on the ideas of being rational and using scientific methods instead of using gut reactions when those approaches give conflicting results.
He does a good job of describing the conflicts between first order desires (e.g. eating sugar) and higher order desires (e.g. the desire not to desire unhealthy amounts of sugar), and why there’s no easy rule to decide which of those desires deserves priority.
He isn’t entirely fair to groups of people that he disagrees with. I was particularly annoyed by his claim that “economics vehemently resists the notion that first-order desires are subject to critique”. What economics resists is the idea that person X is a better authority than person Y about what Y’s desires are or ought to be. Economics mostly avoids saying anything about whether a person should want to alter his desires, and I expect those issues to be dealt with better by other disciplines.
One of the better ideas in the book was to compare the effort put into testing peoples’ intelligence to the effort devoted to testing their rationality. He mentions many tests that would provide information about how well a person has overcome biases, and points out that such information might be valuable to schools deciding which students to admit and employers deciding whom to hire. I wish he had provided a good analysis of how well those tests would work if people trained to do well on them. I’d expect some wide variations - tests for overconfidence can be made to work fairly well, but I’m concerned that people would learn to pass tests such as the Wason test without changing their behavior under conditions when they’re not alert to these problems.

Book review: Why Not?: How to Use Everyday Ingenuity to Solve Problems Big And Small by Barry Nalebuff and Ian Ayres.
This is a very entertaining and somewhat thought-provoking book. I’m uncertain whether it had much effect on my creativity. It certainly demonstrates the authors’ creativity, and gives some insights into how their creative thought processes work. But it’s probably more valuable as a collection of interesting ideas than it is as a recipe for creativity.
While they focus more on presenting interesting ideas than on evaluating how well they would work, the do a decent job of anticipating problems and understanding the relevant incentives.
Possibly the most important idea is mandating anonymity of political campaign contributions (see also the book Voting with Dollars) as an alternative way of ensuring that it’s hard for contributions to influence politicians votes, with plausible suggestions about how to ensure that it’s hard for donors to evade the anonymity rule.
Their examples often leave me wondering why the ideas they describe are so little known (e.g. the anonymity requirement has been tried in 10 states for judicial elections - why hasn’t that been reported widely?).
Another interesting idea is how tests of black boxes in cars (similar to those in planes) cause drivers to drive much more safely (20 to 66 percent declines in accident rates - “Fear of getting caught may be a more powerful motivator than fear of getting killed”).
I am disappointed that it doesn’t have an index.

Book review: Envy: A Theory of Social Behavior by Helmut Schoeck
This book makes a moderate number of interesting claims about envy and its economic effects, interspersed with some long boring sections. The claims are mostly not backed up by strong arguments. It was written 40 years ago, and it shows - his understanding of psychology seems more Freudian than modern.
His most interesting claim is that many societies have more envy than ours, and that prevents them from escaping poverty. An extreme example are the Navaho, who reportedly have no concept of luck or of “personal achievement”, and believe that one person’s success can only come at another’s expense. This kind of attitude is pretty effective at discouraging people in such a society from adopting a better way of growing crops, etc.
Unfortunately, his evidence is clearly of the anecdotal kind that, even if I were to track down the few sources he cites for some of them and convinced myself they were reliable, his examples are too selective for me to believe that he knows whether envy and poverty are correlated. His hypothesis sounds potentially important, and I hope someone finds a way to rigorously analyze it.
He describes a few attempts to create non-envious societies, with kibbutzim being the clearest example. He gives adequate but unsurprising explanations of why they’ve had mixed success.
He claims “The victims claimed by a revolution or a civil war are incomparably more numerous among those who are more gifted and enterprising”, but shows no sign that he knows whether this is true. He might be right, but it’s easy to imagine that he’s been mislead by a bias toward reporting that kind of death more often than the death of a typical person.
He mentions that tax returns have been public in some jurisdictions. I wish he did a better job of examining the costs and benefits of this (one nice example he gives is that people sometimes overreport income in order to appear more credit-worthy than they are).
On page 82, he describes Nazis as having “an almost equally fanatical attachment to the principle of equality”. He seems there to be referring to when they were in power, but somewhere else he implies they moved away from this belief when they gained power. He was born in Austria in 1922, and studied in Munich from 1941 to 1945, which gives him a perspective that we don’t hear much these days. How much of the difference in perspectives is due to his flaws, and how much of it is due to our focus on the worst aspects of Nazism? There’s probably a hint of truth to his position, in that hatred of the Jews partly started with an egalitarian disapproval of their success.
I found a number of other strange claims. E.g. “The incest taboo alone makes possible the co-operative and stable family group.”; “Lee Harvey Oswald’s central motive was envy of those who were happy and successful”; “In 1920 President Woodrow Wilson predicted class warfare in America that would be sparked off by the envy of the many at the sight of the few in their motor cars.”.
He says “No society permits totally uninhibited promiscuity. In every culture there are definite rights of ownership in the sexual sphere, for no society could function unless it had foreseeable and predictable rules as regards selection of the sexual partner.” I’m not sure how close-minded that would have sounded in 1966, but there are cultures today which discredit it fairly well.
If you read this book, I suggest reading only these chapters: 1,3,5,8,13,17,21,22.
Update: Mike Linksvayer has a better review of the book.

Bryan Caplan has a good post arguing democracy produces worse results than rational ignorance among voters would explain.
However, one aspect of his style annoys me - his use of the word irrationality to describe what’s wrong with voter thinking focuses on what is missing from voter thought processes rather than what socially undesirable features are present (many economists tend to use the word irrationality this way). I hope his soon-to-be-published book version of this post devotes more attention to what voters are doing that differs from boundedly rational attempts at choosing the best candidates (some of which I suspect fall into what many of us would call selfishly rational motives even though economists usually classify them as irrational). Some of the motives that I suspect are important are the desire to signal one’s group membership, endowment effects which are one of the many reasons people treat existing jobs as if they were more valuable than new and more productive jobs that can be created, and reputation effects where people stick with whatever position they had in the past because updating their beliefs in response to new evidence would imply that their original positions weren’t as wise as they want to imagine.
Alas, his policy recommendations are not likely to be very effective and are generally not much easier to implement than futarchy (which I consider to be the most promising approach to dealing with the problems of democracy). For example:

Imagine, for example, if the Council of Economic Advisers, in the spirit of the Supreme Court, had the power to invalidate legislation as “uneconomical.”

If I try hard enough, I can imagine this approach working well. But it would take a lot more than Caplan’s skills at persuasion to get voters to go along with this, and it’s not hard to imagine that such an institution would develop an understanding of the concept of “uneconomical” that is much less desirable than Caplan’s or mine.

Book review: Social Mindscapes: An Invitation to Cognitive Sociology by Eviatar Zerubavel
This book is a refreshing and concise collection of interesting tidbits about cultural aspects of human minds. He points out many cultural quirks in our thinking that I suspect many people unconsciously assume are universal beliefs. Sometimes it’s easy to see once you’re provoked to think about it why we should consider something to be a cultural quirk (e.g. putting jam and jelly into two distinct categories rather than one). With others, such as whether the differences between male and female genitalia justify classifying the equivalent parts differently for each sex, I’m almost suspicious enough of his report that western culture had a different answer a couple of centuries ago than it does today to tempt me to check some of his copious references. And there are a few places where his cultural norms seem odd (e.g. his claim that daylight savings time seems natural).
With only 113 pages of actual text, it’s a quick read that would be worth reading for the entertainment value alone, and has the added benefit of shaking up one’s preconceptions.