A week of links

Links this week:

  1. Why idiots succeed.
  2. Rory Sutherland on social norms.
  3. Economics incentives versus nudge (pdf). Don’t forget that basic economic mechanisms can work.
  4. We’re related to our friends.
  5. Are there really trillion dollar bills on the sidewalk?
  6. A bash of the Myers-Briggs test. Personally, I’m a fan of the big five plus g. On g, the heritability of chimp IQ.
  7. Talent versus practice. Talent wins this one.
  8. Throwing away money on brain science.

The wisdom of crowds of people who don’t believe in the wisdom of crowds

MIT Technology reports new research on the “wisdom of the confident”:

It turns out that if a crowd offers a wide range of independent estimates, then it is more likely to be wise. But if members of the crowd are influenced in the same way, for example by each other or by some external factor, then they tend to converge on a biased estimate. In this case, the crowd is likely to be stupid.

Today, Gabriel Madirolas and Gonzalo De Polavieja at the Cajal Institute in Madrid, Spain, say they found a way to analyze the answers from a crowd which allows them to remove this kind of bias and so settle on a wiser answer.

… Their idea is that some people are more strongly influenced by additional information than others who are confident in their own opinion. So identifying these more strongly influenced people and separating them from the independent thinkers creates two different groups. The group of independent thinkers is then more likely to give a wise estimate. Or put another way, ignore the wisdom of the crowd in favor of the wisdom of the confident.

To test this result, they eliminated those who updated their estimates based on that of the crowd:

Madirolas and De Polavieja began by studying the data from an earlier set of experiments in which groups of people were given tasks such as to estimate the length of the border between Switzerland and Italy, the correct answer being 734 kilometers.

After one task, some groups were shown the combined estimates of other groups before beginning their second task. These experiments clearly showed how this information biased the answers from these groups in their second tasks. …

That allows them to divide the groups into independent thinkers and biased thinkers. Taking the collective opinion of the independent thinkers then gives a much more accurate estimate of the length of the border.

The funny thing about this research is that anyone who believes in the wisdom of crowds and updates their belief based on that collective wisdom is then excluded from the collective estimate. The wisdom of crowds needs someone who trusts their own opinion more than that of the crowd. It is similar to the efficient markets hypothesis relying on those who don’t believe in it – if everyone believed markets were efficient, no one would invest effort in finding and acting on information that might affect market prices. That effort is what allows prices to reflect this information.

So who are the confident people who form this more accurate estimate? The Dunning-Kruger effect tells us that the unskilled will be overconfident as they don’t have the cognitive skills to recognise their ineptitude. But despite this effect, the more skilled do tend to be more confident than the unskilled – just not by as much as the skill gap warrants. As a result, eliminating the less confident can still cut the least skilled.

The behaviour genetics to eugenics to Nazi manoeuvre

Recently, I’ve tended to roll my eyes rather than respond to poor commentary on behaviour genetics. But a review by Kate Douglas at New Scientist, in which she pulls the behaviour genetics to eugenics to Nazi manoeuvre, has pointed out a potentially interesting book.

First, from the conclusion to Douglas’s review (actually, not so much a review but a launchpad):

Behaviour geneticists came to see finding high heritability as a justification for their work. But heredity changes depending on the environment. Grow those tomatoes in a regulated greenhouse and almost all the difference in their height will be thanks to their genes; grow them on a sloping, partly shaded field and the effect of heritability is lower.

Nature and nurture are not distinct, and the complexity of their interactions is increasingly apparent in this genomic age. Heritability can’t even be reliably estimated in humans using twin and adoption studies, the method of choice for behaviour geneticists.

All this undermines the supposition that heritability tells us about the cause of a behaviour. In fact, heritability is almost entirely meaningless.

I haven’t yet met a behaviour geneticist who doesn’t understand that heritability can vary with environment. Just look at Eric Turkheimer and friends’ work on heritability of IQ among different socioeconomic groups. The change in heritability across environment tells us something. And if heritability measures are robust across environments (as it is for IQ for most socioeconomic groups), that tells you something too.

But moving on, Douglas’s review is of a new book, Misbehaving Science: Controversy and the Development of Behavior Genetics by Aaron Panofsky. The blurb on the book suggests it might be better than the review, and could contain some interesting history on the debates in the field.

Behavior genetics has always been a breeding ground for controversies. From the “criminal chromosome” to the “gay gene,” claims about the influence of genes like these have led to often vitriolic national debates about race, class, and inequality. Many behavior geneticists have encountered accusations of racism and have had their scientific authority and credibility questioned, ruining reputations, and threatening their access to coveted resources.

In Misbehaving Science, Aaron Panofsky traces the field of behavior genetics back to its origins in the 1950s, telling the story through close looks at five major controversies. In the process, Panofsky argues that persistent, ungovernable controversy in behavior genetics is due to the broken hierarchies within the field. All authority and scientific norms are questioned, while the absence of unanimously accepted methods and theories leaves a foundationless field, where disorder is ongoing. Critics charge behavior geneticists with political motivations; champions say they merely follow the data where they lead. But Panofsky shows how pragmatic coping with repeated controversies drives their scientific actions. Ironically, behavior geneticists’ struggles for scientific authority and efforts to deal with the threats to their legitimacy and autonomy have made controversy inevitable—and in some ways essential—to the study of behavior genetics.

MSiX: Marketing Science Ideas Xchange

For those in or near Sydney at the end of July, there’s an interesting conference in the works – the Marketing Science Ideas Exchange. From the blurb:

The Marketing Science Ideas Xchange (MSiX) is the first event of its type in Australia dedicated to the interface between behavioural science and marketing. The conference will demonstrate why behavioural sciences in general, and behavioural economics in particular, is making such strong headways into advertising. The conference promises to be a mix of theory and practical examples, all housed within a fun and interactive ideas exchange environment.

It will be interesting to go to a behavioural insights conference full of marketers, rather than the usual economists. Marketers have had to be willing to embrace a relatively realistic understanding of human behaviour and, obviously, have been exploiting decision-making biases for years. But I get the sense that they could be more systematic in their approach and adopt a much richer understanding of human nature.

Headlining the conference is Rory Sutherland, the best friend of behavioural science in the ad world (although Rory is happy to keep using the term ‘behavioural economics‘). Watch the video below for a taste of what is on offer. I endorse Rory’s fast train strategy, and recommend googling around for some of this other presentations.

There are some other interesting speakers in the lineup. I recently saw Alex Gyani from the UK’s Behavioural Insights Team (now seconded in the NSW Department of Premier and Cabinet) speak on the need for evidence based policy, and expect he’ll be continuing that theme. The rest of the program is here.

A week of links

Links this week (or closer to a month):

  1. It’s reigning men. How our convict past explains our glass ceiling.
  2. Rory Sutherland on measurebation.
  3. The genetics of investment biases (ungated version). HT: Tyler Cowen.  Basically another confirmation of the three laws of behaviour genetics.
  4. Rats regret bad decisions.
  5. Matt Ridley on fat.
  6. Pulling apart the research on the destructiveness of female hurricanes – Paul Frijters and Andrew Gelman.
  7. Sendhil Mullainathan on the limits to big data.

Genes and socioeconomic aggregates

In April, a Conference on Genetics and Behaviour was held by the Human Capital and Economic Opportunity Global Working Group at the University of Chicago.

The videos for the conference are now up, so as I watch through them, I’ll post links and some brief thoughts. The first session, with videos linked below, was on Genes and Socioeconomic Aggregates. The video and audio are average at times, and you might want to get the slides (links provided where available) as they are hard to read in the video at times. However, there are some good bits in all of the presentations.

Gregory Cochran: Genetics and Society (slides)

Cochran laid out some ideas that should be in the minds of economists, although he does not focus much attention on selling the ideas. Unfortunately, the questions at the end got derailed by epigenetics (my views approximate Cochran’s). One interesting argument by Cochran is that human environments tend be variable, as, in a Malthusian world, good times (when people breed like mad) tend to be followed by bad (too many people) which tend to be followed by good (people died in the bad). As a result, epigenetic transmission based on the current environment may be a poor strategy.

When Cochran posted this video on his blog, some interesting discussion followed in the comments – they are worth checking out.

Enrico Spolaore: Ancestry and the Diffusion of Economic Development: Facts and Questions (slides)

Spolaore touches on his work concerning genetic distance and the diffusion of development (I have posted about it here, here and here). He is extending this work to look at the diffusion of fertility reduction from France (where the demographic transition first occurred), and is getting similar results.

Steven Durlauf: Two Remarks on the Inference of “Macro” Genetic Effects (slides)

I did not get much from Durlauf’s presentation, although some of the questions were interesting. Steve Hsu deflates the “it’s all too hard” message when he points out that animal breeding is now using genetic data.

Henry Harpending: Some Quantitative Genetics Approaches

Harpending discusses his work on how assortative mating can mimic strong selection. I sense this presentation might be difficult to follow if you aren’t familiar with his work (a link to that is here). Not much value in the question session, which gets derailed by issues concerning scaling when estimating heritability.

Aldo Rustichini: Determinants of Inequality and Intergenerational Mobility (slides)

A tough presentation to follow – you need to use the slides to have a chance of getting across it – and not recommended for those not mathematically inclined. The highlight is Greg Cochran trying not to jump out of his chair between the 7 and 8 minute mark due to some comments about heritability. Cochran also deflates the idea that there is a high level of false paternity in humans – for more on that, check out this post by Razib Khan.

Is poverty genetic?

Quamrul Ashraf has pointed me to an episode of Through the Wormhole with Morgan Freeman titled “Is Poverty Genetic?”

The official version of the video is below (payment required?), although it is blocked in Australia (Australians lead the world in digital piracy, despite being willing to pay for content. This sort of thing is why). Below that is another version I managed to find on YouTube – so go for it.

The good: The coverage of Ashraf’s work with Oded Galor on genetic diversity and economic development (my posts on their work are here), experiments on capuchin monkeys’ sense of fairness, and our sense of shame.

The so-so: The opening piece on Eric Turkheimer’s research on the heritability of IQ was OK, but when tied into the next section on differences in brain development, it goes a bit awry. A few concepts that would have helped – IQ heritability increases with age, differences that emerge after birth can be genetic, and genes shape their environment.

The not so good: Kin selection being spun as sacrifice for the benefit of the species. The overall conclusion.

Not sure: The econophysics of poverty.