Evolutionary Dynamics

Nice to see an excellent science writer, Carl Zimmer, write about an excellent mathematical biologist, Martin Nowak, in an article in the New York Times (via The Loom).

Here is a non-technical lecture on evolutionary dynamics by Martin Nowak.

I also look forward to reading his most recent book, Evolutionary Dynamics: Exploring the Equations of Life.

Harvard’s Program for Evolutionary Dynamics was established by Harvard’s then President Larry Summers as a way of using the theory of evolution as a common foundation for biology and economics (I am not sure that he took the other social sciences seriously). Judging from the website, the program’s current mission is now somewhat less ambitious. 

New diversity research scares its author

Harvard political scientist Robert Putnam, author of Bowling Alone, is very nervous about releasing his new research, and understandably so. His five-year study shows that immigration and ethnic diversity have a devastating short- and medium-term influence on the social capital, fabric of associations, trust, and neighborliness that create and sustain communities. He fears that his work on the surprisingly negative effects of diversity will become part of the immigration debate, even though he finds that in the long run, people do forge new communities and new ties.

Putnam’s study reveals that immigration and diversity not only reduce social capital between ethnic groups, but also within the groups themselves. Trust, even for members of one’s own race, is lower, altruism and community cooperation rarer, friendships fewer.[...]

Putnam writes: “Across local areas in the United States, Australia, Sweden Canada and Britain, greater ethnic diversity is associated with lower social trust and, at least in some cases, lower investment in public goods.” [...]

From City Journal. Previous post here, other references and discussion on Stumbling and Mumbling.

Moral Psychology

Jonathan Haidt’s review paper The New Synthesis in Moral Psychology is here.

People are selfish, yet morally motivated. Morality is universal, yet culturally variable. Such apparent contradictions are dissolving as research from many disciplines converges on a few shared principles, including the importance of moral intuitions, the socially functional (rather than truth-seeking) nature of moral thinking, and the coevolution of moral minds with cultural practices and institutions that create diverse moral communities. I propose a fourth principle to guide future research: Morality is about more than harm and fairness. More research is needed on the collective and religious parts of the moral domain, such as loyalty, authority, and spiritual purity.

 Previous post on Haidt here.

Haidt on the five foundations of morality

Here is a video where Jonathan Haidt talks about the five foundations of morality,

1. harm/care,
2. fairness/reciprocity,
3. ingroup/loyalty,
4. authority/respect,
5. purity/sanctity

He makes the point that political liberals (in the American sense) have moral intuitions primarily based upon the first two foundations, and therefore misunderstand the moral motivations of political conservatives, who generally rely upon all five foundations (see also here).

But why exactly five and only five foundations? Any proof that there couldn’t be more?

Accelerating human evolution

The concept of the EEA, the Environment of Evolutionary Adaptedness, never made much sense. In its strong form it is based on the misunderstanding that we evolved during the Stone Age, and then we more or less stopped evolving.

World Science reports on a study by Greg Cochran and John Hawks,

The tra­di­tion­al pic­ture of hu­mans as a fi­n­ished prod­uct be­gan to erode in re­cent years, sci­en­t­ists said, with a crop of stud­ies sug­gesting our ev­o­lu­tion in­deed goes on. But the new­est in­vest­i­ga­tion goes fur­ther. It claims the pro­cess has ac­tu­al­ly ac­cel­er­at­ed.

It al­so down­plays the im­por­tance of a much-scru­ti­nized era around 200,000 years ago, when hu­mans con­sid­ered “ana­tom­i­cally mod­ern” first ap­pear in the fos­sil rec­ord. In the stu­dy, this ep­och e­merges as just part of a vast arc of ac­cel­e­rat­ing change.

“The or­i­gin of mod­ern hu­mans was a mi­nor event com­pared to more re­cent ev­o­lu­tion­ary chang­es,” wrote the au­thors of the re­search, in a pre­sent­a­tion slated for Fri­day in Phi­l­a­del­phia at the an­nu­al meet­ing of the Amer­i­can As­so­ci­a­tion of Phys­i­cal An­th­ro­po­l­o­g­ists. [...]

Hawks and Coch­ran said some of the most no­ta­ble phys­i­cal changes in hu­mans have been ones af­fect­ing the size of the brain case.

A “thing that should prob­a­bly wor­ry peo­ple is that brains have been get­ting smaller for 20,000 to 30,000 years,” said Coch­ran. But brain size and in­tel­li­gence aren’t tightly linked, he added. Also, growth in more ad­vanced brain ar­eas might have made up for the shrinkage, Coch­ran said; he spec­u­lated that an al­most break­neck ev­o­lu­tion of high­er fore­heads in some peo­ples may re­flect this. A study in the Jan. 14 Brit­ish Den­tal Jour­nal found such a trend vis­i­ble in Eng­land in just the past mil­len­ni­um, he noted, a mere eye­blink in ev­o­lu­tionary time.

Research pub­lished in the Sept. 9, 2005 is­sue of the re­search jour­nal Sci­ence by Lahn and col­leagues found that two genes linked to brain size are rap­idly evolv­ing in hu­mans.

Harpending on McKinnon on Evolutionary Psychology

Henry Harpending reviews Susan McKinnon’s book Neo-Liberal Genetics,

…She does not complain that evolutionary psychology is bad science according to standard criteria for evaluating science: Instead she dislikes the “rhetorical structures and strategies of the texts.” She deplores the “narrative” of evolutionary psychology because it “severely constricts the kinds of questions we can ask and the kinds of social worlds we can possibly imagine and endeavor to create for ourselves” (p. 152). In other words McKinnon dislikes the implied constraints on her political fantasies.

Everyone understands and deals with evolutionary psychology. We understand why our cat was easier to toilet train than our baby was: One has the brain of a denning predator and the other of a mobile and occasionally arboreal ape. We also understand that there is no “should” implied in this: No one thinks that children should not be toilet trained. MacKinnon, by contrast, attributes to evolutionary psychologists the belief that saying something “is” is the same as saying that that it “ought” to be. Here, for example, is her notion of what genetic individualism means: “that the ‘public good’ should be replaced by individual responsibility and social services privatized; that profit and capital should be maximized through the deregulation of markets - that is, that competition should run its course unchecked - in a ‘race to the bottom’ - regardless of the social consequences” (p. 44). Notice the “shoulds”, none of which are appropriate…

Despite an occasional interesting insight, most of this book reads like a clone of the dreadful wrong-headed ramblings that were the “sociobiology debate” of the 1970s.

Bob Trivers gets the Crafoord Prize in Biosciences

We are a bit late, but here is the announcement from the Royal Swedish Academy of Sciences,

… Robert Trivers, is one of the small group of pioneering scientists who began to ponder on the social behaviour patterns of animals and how they might have arisen through evolution. Between 1971 and 1976, he launched five ideas that have been of the greatest importance for the development of sociobiology. They have inspired many behavioural ecologists, who have to a large extent confirmed Trivers’s ideas.

Science writers: two of the best

Edward O. Wilson and Steven Pinker are excellent science writers. Both are arguably better science writers than scientists. E.O. Wilson’s work on insects was really good, but his sociobiological ideas are less original than the ideas of e.g. Bill Hamilton or Bob Trivers (a talk by Trivers here). Steven Pinker’s ideas can be summarized as Chomsky plus Tooby & Cosmides; he stands on their shoulders but it it not clear that he sees a whole lot further than they did.

As writers both Wilson and Pinker are prolific, clear, readable, and mostly right. Their books are widely read. Those are great accomplishments.

The person who has done more than anybody else for building the market for science writing is John Brockman, who is a very successful literary agent. He correctly describes himself as an impresario. By creating hype and hoopla around a bunch of nerdish scientists he has promoted the public understanding of science and provided a real public service (see his Edge website, profile in The Guardian (pdf)).

The evolution of altruism

One of the most important 2006 papers in the behavioral sciences is Sam Bowles’ Group Competition, Reproductive Leveling, and the Evolution of Human Altruism (Science vol 314, p 1569). He demonstrates that genetic differences between early human groups are likely to have been great enough so that lethal intergroup competition could account for the evolution of altruism. Crucial for his argument are distinctive human practices such as sharing food beyond the immediate family, monogamy, and other forms of reproductive leveling.

Comment by Yann Klimentidis here.

Here is an article in New Scientist about the paper,

Humans may have evolved altruistic traits as a result of a cultural “tax” we paid to each other early in our evolution, a new study suggests.

The following points are made in Science Week by Robert Boyd,

Market fundamentalism, statism, and community governance

Brad DeLong writes,

How economists use the neoclassical benchmark:

• At Chicago: Assume that the economy is at the neoclassical benchmark, and demonstrate that whatever exists is, in some subtle sense, constrained Pareto-optimal efficient–except where ham-handed government intervention has caused messes.

• At Berkeley: Investigate the deviation from the neoclassical benchmark that can be caused by one single but significant market failure, demonstrate that this deviation matches up to some important feature of the real world, and demonstrate that a clever, subtle, and strategic government intervention can move us to a situation that is constrained Pareto-optimal.

If we were to be unkind, we would call these the market fundamentalist and the statist approaches (in Brad DeLong’s case, a social democratic statism). We can add a third approach, community governance.

• Investigate the deviation from the neoclassical benchmark, demonstrate that this deviation is causes by badly designed government and market institutions that have crowded out community governance. To address this failure, develop institutions and property rights that support community governance as a complement to markets and governments. Note, however, that effective community governance is usually based on insider-outsider distinctions, between Us and Them.

For an introduction to community governance, see

Ostrom, Elinor. Governing the Commons : The Evolution of Institutions for Collective Action. Cambridge: Cambridge University Press, 1990.

Ellickson, Robert C. Order Without Law : How Neighbors Settle Disputes. Cambridge: Harvard University Press, 1994.

You may also want to take a look at

Boehm, Christopher. Hierarchy in the Forest: The Evolution of Egalitarian Behavior. Cambridge: Harvard University Press, 2001.

For researchers doing interesting related work, see the list of network members from the Norms and Preferences Network.

Race, Culture and IQ

The recent debate between James Flynn (of the Flynn Effect) and Charles Murray (of The Bell Curve) has lead to a flurry of posts on various blogs. For a summary, read here. The event, papers, and the video are here.

There is no doubt that there is a gap in IQ scores between black and white Americans. There is no doubt that IQ scores have improved over time, although they may now no longer do so. For example, there are indications that this trend has been arrested or even reversed in Norway and Denmark.

The question is, is the IQ gap between blacks and whites closing? If not, why not? Flynn blames black teenage culture for part of the problem. A earlier cultural explanation was provided by Lee Willerman in 1974 (his work has been quoted e.g. by Orlando Patterson and Richard Nisbett). Willerman showed that there was a difference in IQ between mixed race children who had a black mother, and those who had a white mother. You would expect children of mixed parentage to have the same average IQ regardless of which parent was black. If mothers are more important than fathers to the intellectual socialization of their children, and if the socialization practices of whites favor the acquisition of skills that result in high IQ scores, children of white mothers and black fathers should score higher than children of black mothers and white fathers. In fact, children of white mothers and black fathers have a 9 point IQ advantage over those with black mothers and white fathers. Unless extreme selection factors are at work, this result suggests that much of the black/white IQ gap is environmental.

I don’t know if Willerman’s study has been replicated, but it would certainly be interesting to see a more recent study.

Do IQ tests measure general intelligence?

On Alpha Psy Hugo reports on an interesting paper (Van Der Maas et al., A Dynamical Model of General Intelligence: The Positive Manifold of Intelligence by Mutualism).

Scores on a wide range of intelligence tests tend to correlate positively. From a statistical or psychometric point of view this creates a variable, g that merely indicates the strength of this correlation. If there were no correlation at all, there would be no g, but since the correlations tend to be high, people get excited and many of them take the next step of positing an underlying common cause (also called g). For the psychologists who defend this notion, there is a common variable (modulating, say, the way your neurons fire) that influences on the measures of all of these intelligence tests, thus creating the observed correlation. However researchers from the University of Amsterdam are challenging the common wisdom and suggest an explanation for the correlation that doesn’t need a common cause.

How important is intelligence? On Dilbert Blog Scott Adams says,

Discrimination and Ethnic Nepotism

We all discriminate all the time. As Walter Williams says (via Stefan Karlsson),

“When I married Mrs. Williams, I discriminated against other women. Even though I occasionally think about equal opportunity, Mrs. Williams demands continued discrimination.”

Chris Dillow asks, “Why do people identify so much with their ethnicity?”

One argument is that a bias in favor of one own’s ethnic group is an example of kin selection. A map of a person’s ancestors is not a tree, but a bush, where everyone in an ethnic group is related to everyone else, possible on average as closely as first cousins. Identification with one’s ethnic group is therefore rational and makes perfect sense in evolutionary terms.

Another argument is that it is more efficient to work with someone belonging to your own ethnic group. If you share a common language and a common set of values, it is much easier to evaluate how far you can trust another person.

Here is a report in ScienceNOW Daily News on a recent study,

“When it comes to nepotism, people from indigenous tribes are not so different from you and me. Given the choice between punishing a fellow tribesman or a member of a neighboring tribe for the same crime, New Guinea natives protect their own, according to new research. The study suggests that favoritism knows no cultural boundaries.

Economic Man and Economic Monkey

But men and monkeys have a sense of fairness and an aversion to inequity. In a fascinating study, Sarah Brosnan and Frans de Waal showed that capuchin monkeys react negatively when another individual gets a better reward for the same or less effort on a specific task.

Pairs of brown capuchin monkeys (Cebus apella), were placed next to each other and trained to exchange a token with human handlers to receive a reward, in most cases, a piece of cucumber. Partners of capuchins who made the swap either received the same reward (a cucumber slice), or a better reward (a grape, a more desirable food), for the same amount of work or, in some cases, for performing no work at all. Capuchins who witnessed unfair treatment and failed to benefit from it often refused to conduct future exchanges, would not eat the cucumbers they received for their labors, and in some cases, threw food rewards at human researchers.

Like the Ultimatum Game in experimental economics, this experiment demonstrates inequity aversion. In the Ultimatum Game two parties interact anonymously and only once. The first player proposes how to divide a sum of money with the second party. If the second player rejects this division, neither gets anything. If the second accepts, the first gets what he proposed and the second gets the rest. Low offers are often rejected by the second party. Since an individual who rejects a positive offer is choosing to get nothing rather than something, that individual is not acting to maximize his economic gain.

In a study by Joseph Henrich et al., In Search of Homo Economicus: Behavioral Experiments in 15 Small-Scale Societies the researchers reported,

Recent investigations have uncovered large, consistent deviations from the predictions of the textbook representation of Homo Economicus: in addition to their own material payoffs, many experimental subjects appear to care about fairness and reciprocity and reward those who act in a cooperative manner while punishing those who do not even when these actions are costly to the individual…

We can summarize our results as follows. First, the canonical model is not supported in any society studied. Second, there is considerably more behavioral variability across groups than had been found in previous cross-cultural research, and the canonical model fails in a wider variety of ways than in previous experiments…

“Economic man” doesn’t exist. Neither, it seems, does “economic monkey”.

Update: See Joseph Henrich’s critique of Brosnan and de Waal here.

Economic Man is a Straw Man

People wanting to criticize economics often set up a straw man, “Economic Man”, a purely rational and selfish creature who can easily be knocked down. However, economics has moved beyond this caricature (well, maybe business school economics hasn’t, you still get a Panglossian “Greed is Good” triumphalism in B schools). Read e.g. this paper in Science,

When Does ‘Economic Man’ Dominate Social Behavior?,
Colin F. Camerer and Ernst Fehr

The canonical model in economics considers people to be rational and self-regarding. However, much evidence challenges this view, raising the question of when ‘‘Economic Man’’ dominates the outcome of social interactions, and when bounded rationality or other-regarding preferences dominate. Here we show that strategic incentives are the key to answering this question. A minority of self-regarding individuals can trigger a ‘‘noncooperative’’ aggregate outcome if their behavior generates incentives for the majority of other-regarding individuals to mimic the minority’s behavior. Likewise, a minority of other-regarding individuals can generate a ‘‘cooperative’’ aggregate outcome if their behavior generates incentives for a majority of self-regarding people to behave cooperatively… Recently developed theories of other-regarding preferences and bounded rationality explain these findings and provide better predictions of actual aggregate behavior than does traditional economic theory.

See also the papers on the websites of these very good scientists,

Colin Camerer

Ernst Fehr

Herbert Gintis

Selfishness and Altruism

Over on Environmental Economics, J.S. writes (in Self Interest is the Answer),

There are many people who are motivated to protect the environment (or promote human rights or other progressive activities) because of a deep sense that it is the right thing to do. These are the type of people who if confronted with a situation where they had to risk bodily harm to save a fellow creature would do so not because of any desire for reward or material gain, but because they couldn’t imagine not doing so. They have incorporated a sense of compassion and integrity into their conception of their self-interest to such a degree that they couldn’t live with themselves if they didn’t act in ways that reduced suffering in the world. This perhaps is the highest form of self-interest, but it is self-interest nonetheless, albeit a highly evolved form.

That is a really convoluted argument. Altruistic behavior is altruistic, not a highly evolved form of self-interest. If people engage in behavior with a net negative benefit to themselves, e.g. altruistic punishment, why call it self-interested? It is not. Altruistic punishment promotes cooperation and does a lot of good. You may feel good about engaging in it, but it is still altruistic.

And as Adam Smith said in The Theory of Moral Sentiments,

“How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortunes of others, and render their happiness necessary to him, though he derives nothing from it, except the pleasure of seeing it.”