Archive for the ‘The Human Mind’ Category

The Chimera Hypothesis

Tuesday, March 2nd, 2010

The Chimera Hypothesis: Homosexuality and Plural Pregnancy makes the surprising claim that:

at least 50-70% of healthy adults are chimeric to some extent.

The hypothesis can explain some homosexual and transgender tendencies, and suggests some reproductive advantages that offset those reproductive disadvantages:

Therefore, women prone to having more than one egg fertilized, but whose pregnancies only resulted in only one live birth, would have the optimum level of fertility. A side effect of this could be an increased incidence of chimerism in human children … even a relatively small increase in female fertility, which is really the limiting factor in human population growth, could outweigh the disadvantage of less fertility in a small number of male infants.

One observation that this hypothesis doesn’t explain is why there are many more homosexuals than transgenders. So my guess is that it explains only a modest fraction of the homosexuality that we observe, but might explain the observed frequency of transgenders fairly well.

Impro

Friday, January 29th, 2010

Book review: Impro: Improvisation and the Theatre, by Keith Johnstone.

This book describes aspects of the human mind and social interactions which actors often need to analyze more explicitly than others, because actors need to be aware of the differences between various roles/personalities that they play, whereas unconscious understanding is adequate for people who only interact as a single personality.

The best chapter is about status, and emphasizes the important role that status games play in most social situations and how hard it is to be aware of one’s status-related behavior.

One disturbing claim he makes is that “acquaintances become friends when they agree to play status games together”. I’m very tempted to deny that I do that (as he predicts most people will deny acting). But I know there’s more happening in social interactions than I’m aware of, so I’m hesitant to dismiss his claim.

The chapter on spontaneity has apparently important insights about the role self-censorship plays in spontaneity and creativity. But I find it hard enough to change my behavior in response to those insights that I can’t be confident he’s correct.

He has the insight that “personality” functions as a public-relations department for the mind. Personality doesn’t seem like quite the right word here, but this is remarkably similar to an idea that Geoffrey Miller later developed from evolutionary theory in his excellent book The Mating Mind.

The chapter on masks and trance is strange and hard to evaluate.

The Value of Cute Kittens

Wednesday, December 23rd, 2009

This research suggests you should look at pictures of cute kittens before starting tasks that require a lot of dexterity, and possibly a broader set of tasks that require caution.

What Intelligence Tests Miss

Saturday, December 12th, 2009

Book review: What Intelligence Tests Miss – The Psychology of Rational Thought by Keith E. Stanovich.

Stanovich presents extensive evidence that rationality is very different from what IQ tests measure, and the two are only weakly related. He describes good reasons why society would be better if people became more rational.

He is too optimistic that becoming more rational will help most people who accomplish it. Overconfidence provides widespread benefits to people who use it in job interviews, political discussions, etc.

He gives some advice on how to be more rational, such as thinking the opposite of each new hypothesis you are about to start believing. But will training yourself to do that on test problems cause you to do it when it matters? I don’t see signs that Stanovich practiced it much while writing the book. The most important implication he wants us to draw from the book is that we should develop and use Rationality Quotient (RQ) tests for at least as many purposes as IQ tests are used. But he doesn’t mention any doubts that I’d expect him to have if he thought about how rewarding high RQ scores might affect the validity of those scores.

He reports that high IQ people can avoid some framing effects and overconfidence, but do so only when told to do so. Also, the sunk cost bias test looks easy to learn how to score well on, even when it’s hard to practice the right behavior – the Bruine de Bruin, Parker and Fischhoff paper than Stanovich implies is the best attempt so far to produce an RQ test lists a sample question for the sunk costs bias that involves abandoning food when you’re too full at a restaurant. It’s obvious what answer produces a higher RQ score, but that doesn’t say much about how I’d behave when the food is in front of me.

He sometimes writes as if rationality were as close to being a single mental ability as IQ is, but at other times he implies it isn’t. I needed to read the Bruine de Bruin, Parker and Fischhoff paper to get real evidence. Their path independence component looks unrelated to the others. The remaining components have enough correlation with each other that there may be connections between them, but those correlations are lower than the correlations between the overall rationality score and IQ tests. So it’s far from clear whether a single RQ score is better than using the components as independent tests.

Given the importance he attaches to testing for and rewarding rationality, it’s disappointing that he devotes so little attention to how to do that.

He has some good explanations of why evolution would have produced minds with the irrational features we observe. He’s much less impressive when he describes how we should classify various biases.

I was occasionally annoyed that he treats disrespect for scientific authority as if it were equivalent to irrationality. The evidence for Big Foot or extraterrestrial visitors may be too flimsy to belong in scientific papers, but when he says there’s “not a shred of evidence” for them, he’s either using a meaning of “evidence” that’s inappropriate when discussing the rationality of people who may be sensibly lazy about gathering relevant data, or he’s simply wrong.

Create Your Own Economy (?)

Friday, August 21st, 2009

Book review: Create Your Own Economy: The Path to Prosperity in a Disordered World by Tyler Cowen.

This somewhat misleadingly titled book is mainly about the benefits of neurodiversity and how changing technology is changing our styles of thought, and how we ought to improve our styles of thought.

His perspective on these subjects usually reflects a unique way of ordering his thoughts about the world. Few things he says seem particularly profound, but he persistently provides new ways to frame our understanding of the human mind that will sometimes yield better insights than conventional ways of looking at these subjects. Even if you think you know a good deal about autism, he’ll illuminate some problems with your stereotypes of autistics.

Even though it is marketed as an economics book, it only has about one page about financial matters, but that page is an eloquent summary of two factors that are important causes of our recent problems.

He’s an extreme example of an infovore who processes more information than most people can imagine. E.g. “Usually a blog will fail if the blogger doesn’t post … at least every weekday.” His idea of failure must be quite different from mine, as I more often stop reading a blog because it has too many posts than because it goes a few weeks without a post.

One interesting tidbit hints that healthcare costs might be high because telling patients their treatment was expensive may enhance the placebo effect, much like charging more for a given bottle of wine makes it taste better.

The book’s footnotes aren’t as specific as I would like, and sometimes leave me wondering whether he’s engaging in wild speculation or reporting careful research. His conjecture that “self-aware autistics are especially likely to be cosmopolitans in their thinking” sounds like something that results partly from the selection biases that come from knowing more autistics who like economics than autistics who hate economics. I wish he’d indicated whether he found a way to avoid that bias.

More on the Flynn Effect

Sunday, August 2nd, 2009

This review by Cosma Shalizi of James Flynn’s book What Is Intelligence? provides some interesting criticisms of Flynn (while agreeing with much of what Flynn says).

Shalizi’s most important argument is that Flynn and others who attach a good deal of importance to g haven’t made much of an argument that it measures a single phenomenon.

After a century of IQ testing, there is still no theory which says which questions belongs on an intelligence test, just correlational analyses and tradition.

Flynn and others have good arguments that whatever g measures is important. But Shalizi leaves me with the impression that the only way to decide whether it’s a single phenomenon is to compare its usefulness to models which describe multiple flavors of intelligence. So far those attempts that I’ve looked at seem underwhelming. Maybe that means trying to break down intelligence into components which deserve separate measures isn’t fruitful, but it might also mean that the people who might do a good job of it have been scared away by the political controversies over IQ.

HT Kenny Easwaran.

Greatness

Tuesday, June 23rd, 2009

Book review: Greatness: Who Makes History and Why by Dean Keith Simonton.

This broad and mediocre survey of psychology of people who stand out in history probably contains a fair number of good ideas, but it’s hard to separate them from the many ideas that are questionable guesses. He’s inconsistent about distinguishing his guesses from claims backed by good evidence.

One of the clearest examples is his assertion that childhood adversity builds character. He presents evidence that eminent figures were unusually likely to have had a parent die early, and describes this as the “most impressive proof” of his claim. He ignores the possibility those people come from families with a pattern of taking sufficiently unusual risks to explain that evidence.

In other places, he makes mistakes which seemed reasonable when the book was published, such as “Mendelian laws of inheritance are blind to whether an individual is first-born or later-born” (parental age has a measurable effect on mutation rates).

He avoids some of the worst mistakes that a psychology of history could make, such as trying to psychoanalyze individuals without having enough information about them.

He mentions some approaches to analyzing presidential addresses and corporate letters to stockholders, which have some potential to be used in predicting whether leaders have the appropriate personality for their jobs. I wonder what would happen if many voters/stockholders demanded that leaders pass tests of this nature (I’m assuming the tests can be scored objectively, but that may be shaky assumption). I’m confident that we’d get leaders with rhetoric that passes those tests. Would that simply mean the leaders change their rhetoric, or would it be hard enough to maintain a mismatch between rhetoric and thought patterns that we’d get leaders with better thought patterns?

Autism and Rationality

Friday, March 27th, 2009

This paper reports that people with autistic spectrum symptoms are less biased by framing effects. Unfortunately, the researchers suggest that the increased rationality is connected to an inability to incorporate emotional cues into some decision making processes, so the rationality comes at a cost in social skills.

Some analysis of how these results fit in with the theory that autism is the opposite end of a spectrum from schizophrenia can be found here:

It seems that the schizophrenic is working on the basis of an internal model and is ignoring external feedback: thus his reliance on previous response.I propose that an opposite pattern would be observed in Autistics with Autistics showing no or less mutual information, as they have poor self-models; but greater cross-mutual information , as they would base their decisions more on external stimuli or feedback.

The 10,000 Year Explosion

Sunday, March 15th, 2009

Book review: The 10,000 Year Explosion: How Civilization Accelerated Human Evolution by Gregory Cochran and Henry Harpending.

This provocative book describes many recent genetic changes in humans, primarily those resulting from the switch from hunter-gatherer lifestyles to agricultural lifestyles. Large changes in diets and disease are the simplest causes of change, but the book also describes subtler influences that alter human minds as well.

I had believed that large populations rarely evolve very fast due to the time required for a mutation to spread. This is true for mutations which provide negligible selective advantage, but the book shows that it’s plausible that a number of mutations have recently gained a large enough selective advantage that the rate at which they become widespread is only modestly dependent on population size. Also, the book makes a surprising but plausible claim that the larger supply of mutations in large populations can mean large populations evolve faster than small populations.

The book is occasionally not as rigorous as I would like. For instance, the claim that Ashkenazi “must have been exposed to very similar diseases” as their neighbors is false if the diseases were sexually transmitted.

Most of their claims convince me that conventional wisdom underestimates how important human genetic differences compared to cultural differences, but leave plenty of room for doubt about the magnitude of that underestimation.

They provide an interesting counterargument to the claim that differences within human populations are larger than the differences between populations. Their belief that differences between populations are more important seems to rest on little more than gut feelings, but they convince me that the conventional wisdom they’re disputing is poorly thought out.

They convinced me to take more seriously the possibility that some Neanderthal genes have had significant effects on human genes, although I still put the odds on that at less than 50 percent.

Stroke of Insight

Wednesday, March 4th, 2009

Book review: My Stroke of Insight: A Brain Scientist’s Personal Journey by Jill Bolte Taylor.

This book provides a unique description of the differences between the left and right sides of the brain, because she experienced about as big a decrease in the functioning of her left hemisphere as anyone who has recovered enough to write about it. It’s a very quick read, but didn’t have as much information as I’d hoped.

She makes plausible claims (with minimal mysticism) that her stroke helped her experience nirvana and continues to help her choose to have the best parts of her brain dominate her personality. It makes me wish there were something better than the Wada test that would enable the rest of us to more safely experiment with such experiences.

It helps me understand what I’m not accomplishing when I try (with little success) to meditate, but it appears that her advice for how to do better only works for people who are starting with a mind that is less strongly dominated by the left brain than mine.

It’s important to remember that the parts of her brain that are reporting the benefits of her experience are the ones that survived. We have little information about how the parts of her brain that died would have evaluated the experience.