In my review of Boyd and Richerson’s The Origin and Evolution of Cultures, I noted that I was not completely happy with their treatment of group selection. This post catalogues some of my thoughts.

Boyd and Richerson open their group selection discussion by noting that selection can be broken down into between-group and within-group selection (as per the Price equation – and given this equation can be developed for multiple levels, we refer to “multi-level selection”). But in their analysis of what they call group selection, they do not practically use this framework and there are no attempts to decompose the levels of selection despite the initial framing of the problem around the ability to do this. Part of the reason for the lack of decomposition between the levels is that Boyd and Richerson generally (but not always) have another conception of group selection in mind – differential reproduction and spread of groups. But that is part of what makes the initial framing deceiving.

This problem becomes apparent when they start to discuss situations where it is unclear at what level the selection is occurring. Take the following:

Payoff-biased imitation means people will preferentially copy individuals who get higher payoffs. The higher an individual’s payoff, the more likely that individual is to be imitated. If individuals have occasion to imitate people in neighboring groups, people from cooperative populations will be preferentially imitated by individuals in noncooperative populations because the average payoff to individuals from cooperative populations is much higher than the average payoff of individuals in noncooperative populations. Boyd and Richerson (2000) have shown that, under a wide range of conditions (and fairly quickly), this form of cultural group selection will deterministically spread group-beneficial behaviors from a single group (at a group-beneficial equilibrium) through a meta-population of other groups, which were previously stuck at a more individualistic equilibrium.

So, individuals copy people from more successful groups and the trait then spreads within those  groups. Is this actually group selection? Why does the trait spread in the new group – doesn’t this require individual advantage?

The paper referred to in this quote – Boyd and Richerson (2000) – is also contained in the book, and it describes a model with the spread of norms about drinking. Drinking has negative long-term consequences, but some people drink due to strong discounting. However, the presence of people with puritanical (rather than tolerant) norms can increase the cost of drinking due to social disapproval, meaning populations with puritan norms are better off as a whole than populations of tolerant people.

As people with tolerant and puritanical norms get on each other’s nerves, an isolated group’s members will tend to have the same norm. But given the lower number of drinkers in the puritan groups, the puritan groups will have the higher total payoff. Thus, if groups can mix, the puritan norms may spread as people copy the most successful individuals from other groups. Boyd and Richerson describe this as group selection, but the spread of the norms within groups after mixing demonstrates a degree of individual benefit. At what level are the dynamics dominant?

In other parts of the book, it is difficult to disentangle what the trait under group selection is. For example, when Boyd and Richerson write of the spread of ritualised cannibalism in New Guinea and the associated spread of the disease kuru, they describe the process as group selection. But is the relevant cultural trait eating kuru? Conforming to group rituals? Conforming to rituals concerning cannibalism? Which of these is being selected affects the assessment of the level of selection. Educated guesses can be made, but it is hard work.

These examples indicate a degree of looseness in Boyd and Richerson’s use of the term group selection. At times the term seems to be thrown at any dynamics that involve groups, with no clear definition of what group selection is and no attempt to place the observed behaviour in the context of the definition. This is, of course, a broader issue in much of the literature concerning group selection.

Having said this, as I mentioned in my review, I am not averse to the idea of examining cultural evolution in a group selection framework. I like many of Boyd and Richerson’s models and the descriptions of the dynamics, even if I consider the group selection label has been incorrectly applied. And it is possible that some of my complaints above could be dealt with through better explanation. But Boyd and Richerson use the term group selection so loosely that it is hard to agree with their use, particularly as I’m not sure what exactly I would be agreeing with. For the moment I prefer to describe their overall approach as “cultural group dynamics”.

I missed Dienekes’s post when the debate on Ashraf and Galor’s paper on genetic diversity and economic growth was going strong, but he makes some interesting points on whether genetic diversity would be positive or not.

Genetic diversity is, in general, a good thing for a population, for a simple reason: adaptation via natural selection depends on the existence of variation (there cannot be selection in the absence of alternatives). Other things being equal, a population possessing a greater amount of genetic diversity has a greater probability of already possessing adaptive alleles that might be necessary to meet new environmental challenges (e.g., pathogens).

Of course, for the relevant genes, natural selection eliminates the diversity. In the long-run, we generally won’t see diversity in the most strongly selected traits. Dienekes continues:

But, we must also remember that genetic diversity can be partitioned to what is useful, neutral, or deleterious. We ought to be thankful that our Major Histocompatibility Complex (MHC) region is diverse, largely indifferent whether neutrally involving microsatellite loci have higher or lower allele variance in two populations, and a little concerned if there is an abundance of mildly deleterious rare variants sprinkled in our genomes, or a strong-effect disease-causing variant in one locus. …

And, indeed, even the boundaries between the useful/neutral/deleterious categories are blurred. Deleterious anaemia-causing mutations are known to have benefits of malaria-resistance. Neutral variants may be “useful” ones in waiting: for example, lactase persistent mutants may have existed in the human species for hundreds of thousands of years, appearing and re-appearing by mutation, but it is when they encountered cow’s milk and the need to drink it that they shifted from “neutral” to “useful”. And, even useful alleles can cease to be so, e.g., the eradication of swamps and malaria in Greece has removed the benefit of malaria-resistence, and left only the harm of anaemia.

The measures of genetic diversity used by Ashraf and Galor are based on non-protein coding regions of the genome, so may be neutral. However, the genetic diversity measured using these non-protein coding regions may be reflected in the functional diversity that was initially available to populations when the new populations were established.

It raises the question of what form of genetic diversity would be useful in a population. In many qualitative traits such as intelligence, diversity would not seem to be helpful. Yet an economy with significant specialisation and trade is likely to have roles for a broad range of people.

Dienekes also questions whether the genetic diversity in today’s populations is the result of the Out-of-Africa event.

Evidence has been slowly and steadily accumulating, that people who live in different parts of the world today are not necessarily the same people of the ones who lived there a few thousand years ago. Migration and admixture have changed the landscape of human genetic variation: migration by expanding “narrow” genetic pools into much wider territories, and admixture by increasing diversity in contact zones.

I do not see this point as being fatal for the genetic diversity and economic growth hypothesis, as migratory distance from Africa is correlated with genetic diversity even with localised migration and admixture. Perhaps as understanding of migrations and admixture is developed, there may be potential for more refined analysis of hypotheses such as Ashraf and Galor’s.

The preliminary program for January’s American Economic Association annual meeting is available, with a session dedicated to genoeconomics. I’ve posted on the first of the papers before.

Jan 06, 2013 8:00 am, Manchester Grand Hyatt, Elizabeth Ballroom C
American Economic Association

Genes and Economic Behavior (D8)
Presiding: DAVID LAIBSON (Harvard University)

The Genetic Architecture of Economic and Political Preferences
DAVID CESARINI (New York University)
CHRIS DAWES (New York University)
CHRISTOPHER F. CHABRIS (Union College)
MAGNUS JOHANNESSON (Stockholm School of Economics)
DAVID I. LAIBSON (Harvard University)

Meta-Analysis of Genome-Wide Association Studies of Educational Attainment
DANIEL J. BENJAMIN (Cornell University and NBER)
DAVID CESARINI (New York University)
PHILIPP KOELLINGER (Erasmus University Rotterdam)
MATHIJS VAN DER LOOS (Erasmus University Rotterdam)
NIELS RIETVELD (Erasmus University Rotterdam)

Genetic Modulation of the Effects of Tobacco Taxation on Use
JASON FLETCHER (Yale University)

Meta-Analysis of Genome-Wide Association Studies of Well-Being
JAN-EMMANUEL DE NEVE (University College London & Centre for Economic Performance (LSE))
MEIKE BARTELS (VU University Amsterdam)
BOB KRUEGER (University of Minnesota)
NIELS RIETVELD (Erasmus University Rotterdam)
PHILIPP KOELLINGER (Erasmus University Rotterdam)

Discussants:
DAVID I. LAIBSON (Harvard University)
ALDO RUSTICHINI (University of Minnesota)
ANDREW CAPLIN (New York University)
JOHN CAWLEY (Cornell University)

Evolutionary biology also gets a slot in the session on the historical origins of comparative development:

Jan 06, 2013 10:15 am, Manchester Grand Hyatt, Randle A
American Economic Association

On the Historical Origins of Comparative Development (O1)
Presiding: HOLGER STRULIK (University of Goettingen)

Genetic Diversity and Ethnic Civil Conflict
CEMAL EREN ARBATLI (Brown University)
QUAMRUL ASHRAF (Williams College)
ODED GALOR (Brown University)

This paper might be an interesting addition to the debate about Ashraf and Galor’s paper on genetic diversity and economic development. The potential for conflict due to higher levels of genetic diversity is half of their argument for a hump-shaped relationship between genetic diversity and economic development, and it could do with some support.

From Matt Ridley in the Wall Street Journal:

Back in the hunter-gatherer Paleolithic, inequality had reproductive consequences. The successful hunter, providing valuable protein for females, got a lot more mating opportunities than the unsuccessful. So it’s possible that men still walk around with a relatively simple equation in their brains, namely that relative success at obtaining assets results in more sexual adventures and more grandchildren.

If so, this might explain why it is relative, rather than absolute, inequality that matters so much to people today. In modern Western society, when even relatively poor people have access to transport, refrigeration, entertainment, shoes and plentiful food, you might expect that inequality would be less resented than a century ago—when none of those things might come within the reach of a poor person. What does it matter if there are people who can afford private jets and designer dresses?

But clearly that isn’t how people think. They resent inequality in luxuries just as much if not more than inequality in necessities. They dislike (and envy) conspicuous consumption, even if it impinges on them not at all. What hurts is not that somebody is rich, but that he is richer.

Females care about a male’s resources as they can be used by the female to raise their children, and they may be a signal of the male’s underlying genetic quality.

This preference exists despite the apparently declining importance of additional resources in a modern context. In a rich country, all necessities can be easily provided, and investment over a certain threshold likely has limited effect on child quality. However, another less mentioned reason behind the desire for more resources is the potential for an environmental shock. Inequality in luxuries may suddenly become important as those with ample resources are better able to survive a new, constrained environment.

A commonly used example of this is survivorship on the Titanic (unfortunately of most recent note due to the self-plagiarism issues involving Bruno Frey and colleagues). Of the first, second and third class passengers on the Titanic, 62 per cent, 41 per cent and 25 per cent survived respectively (I pulled these numbers from Gandolfi, Gandolfi and Barash’s Economics as an Evolutionary Science). Similar patterns of survival occur in war, with the wealthy better able to flee or buy their safety. Resources currently allocated to luxuries can be diverted to necessities when required.

The Titanic example and other modern equivalents are too recent to have shaped our evolved psyche, but this pattern likely has been around since human’s started to accumulate wealth. Thus, even in times of plenty, the potential for a shock to the system may still lie at the back of people’s minds.

As an aside, my work with Juerg Weber and Boris Baer also gets a mention in Ridley’s piece.

Two papers in which Gerald Crabtree argues that human intelligence has declined since a peak thousands of years ago (Part I and Part II) have been the subject of the popular science media rounds over the last week (such as this piece in The Independent).

Crabtree’s argument has two components. The first is that intelligence is fragile and vulnerable to genetic load (not that he uses the term genetic load). He estimates that within the last three thousand years, the average person would have accumulated at least two mutations that have harmed our intelligence.

The second component is that selection pressure on intelligence eased when humans started to live in supportive societies where failures of judgement are no longer fatal. Adaptations relating to immunity would have been more important. Without this selection pressure, the negative mutations are no longer eliminated from the population.

I’m relatively sympathetic to the first limb, and the idea that thousands of genes influence intelligence (although I’m not convinced that Crabtree has put together the best case for it). For the second, however, Crabtree overestimates the existence of a social support web over recent millennia and underestimates the need for intelligence to survive in agricultural societies. I am not sure what level of social security existed in medieval Europe, but I expect it was minimal and probably little different from the web of family support received in a hunter-gatherer group. Crabtree appears to be projecting today’s supportive conditions back further than they existed.

Crabtree anticipates one response to his argument, that intelligence can still be favoured by sexual selection:

Intellectual capacity and emotional stability have mating advantages that would reduce the rate at which mutations affecting these traits become fixed in our genome. This is true, but I fear does not take into account the extreme selection required to maintain traits dependent upon thousands of genes with reduced heritability. A hunter–gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his/her progeny, whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate. Clearly, extreme selection is a thing of the past.

The problem is that Crabtree does not see sexual selection as an “extreme” selective force, when it is. Consider Wade and Shuster’s estimate that sexual selection accounts for 55 per cent of total selection in homo sapiens. Or take Greg Clark’s data from A Farewell to Alms, with the rich having twice the children of the poor. The link between resources and reproductive success is strong across societies, and assuming a link between resources and intelligence (which if anything appears to be getting stronger), the intelligent have been reaping a reproductive bounty for some time. For those less fortunate, survival without reproduction is still a genetic dead-end.

At the opening of the first paper, Crabtree offers a wager on his hypothesis.

I would wager that if an average citizen from Athens of 1000 BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas, and a clear-sighted view of important issues. Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues. I would also make this wager for the ancient inhabitants of Africa, Asia, India, or the Americas, of perhaps 2000–6000 years ago.

Crabtree does not seem to realise that this experiment has been run before. Over the last couple of hundred years, members of previously isolated hunter-gatherer tribes have been incorporated into modern societies. Those hunter-gatherers’ lives of day-to-day danger, by Crabtree’s theory, should have kept them out of the downward intelligence spiral that the rest of us has been subject to. We have a reference point that we can use.

Part of the problem with Crabtree’s argument is that he has a different conception of intelligence to that in psychometry. He talks of spatial abilities, which are hard to replicate using robots, as being of a different order to playing “superficially intellectual” chess. I’d be more sympathetic to Crabtree’s argument if he limited his argument to spatial abilities, and we could look at the spatial abilities of hunter-gatherers. Different skills were almost certainly required post-agriculture. But trying to turn questions around the need for spatial abilities into an argument of general intellectual decline is stretching it too far.

Crabtree also suggests that genomic sequencing may also shed some light on this question. I agree, but I expect that the increasing evidence of accelerating adaptive evolution of humans will only grow stronger with that genomic evidence, and that intelligence is likely to be one of those selected traits.

Last week, I presented my paper on conspicuous consumption and economic growth at the annual PhD Conference in Economics and Business. The basic argument of the paper is that the evolution of the propensity to engage in conspicuous consumption is a factor underlying modern economic growth, as conspicuous consumption requires productive activity to produce the resources to consume.

One of the great features of the conference is that each presenter is allocated a discussant who reviews the paper and presents a critique – and the task is taken seriously. Paul Frijters from the University of Queensland was my discussant, and he made a few interesting points (a copy of his presentation is here).

Frijters’s major criticism is that I should not link the evolution of conspicuous consumption to the Industrial Revolution. This critique suggests that I have done a poor job at framing my argument, as it is not my intention to argue that the evolution of the propensity to signal quality through conspicuous consumption was a specific trigger of the Industrial Revolution. Rather, it provides one of the foundations for the Industrial Revolution to occur – and that foundation could have been laid some time before it.

To move away from the Industrial Revolution, Frijters suggests three alternatives for the paper (the first two as throwaway ideas, the third as a more serious suggestion):
1. Use the model to further dispel the myth that the Industrial Revolution had anything to do with evolutionary selection.
2. Switch from economics to something biological, such as why some animal species don’t signal status and others do.
3. Talk not of changes within a few hundred years, but instead about human sub-populations.

On the first suggestion, evolutionary models can be very fast. The basic model in the conspicuous consumption paper required only 10 or so generations for the take-off. In some ways, it is the Industrial Revolution like take-off in the simulations that gives the impression that we are trying to explain the Industrial Revolution. Even if we rule out conspicuous consumption as a specific trigger, there are plenty of other evolved traits worth considering.

However, I agree with Frijters that looking at human sub-populations will be vital in picking apart this topic. Better demographic data is being developed and I am hopeful that the next few years will see cheaper genome sequencing driving the development of interesting longitudinal data on selection pressure. Ultimately, an evolutionary theory of the Industrial Revolution must stand or fall based on the ability to differentiate between populations that experienced rapid technological growth, and those that did not.

On that point, there is not much evidence of biologically mediated differences in conspicuous consumption between populations – particularly in a way that would support conspicuous consumption as being that specific Industrial Revolution trigger. Conspicuous consumption is relatively ubiquitous, with only the form varying. Cross-population analysis will be more interesting when we consider other economic traits.

As an aside, Frijters has a book coming out next year (with Gigi Foster) – An Economic Theory of Greed, Love, Groups and Networks – that might be worth a look.

From the Journal of Neuroscience, Psychology, and Economics (ungated prepublication version here):

Genes, economics, and happiness
De Neve, Jan-Emmanuel; Christakis, Nicholas A.; Fowler, James H.; Frey, Bruno S.

We explore the influence of genetic variation on subjective well-being by employing a twin design and genetic association study. In a nationally representative twin sample, we first show that ∼33% of the variation in life satisfaction is explained by genetic variation. Although previous studies have shown that baseline happiness is significantly heritable, little research has considered molecular genetic associations with subjective well-being. We study the relationship between a functional polymorphism on the serotonin transporter gene (5-HTTLPR) and life satisfaction. We initially find that individuals with the longer, transcriptionally more efficient variant of this genotype report greater life satisfaction (n = 2,545; p = .012). However, our replication attempts on independent samples produce mixed results, indicating that more work needs to be done to better understand the relationship between this genotype and subjective well-being. This work has implications for how economists think about the determinants of utility, and the extent to which exogenous shocks might affect individual well-being.

While I’m glad this work is being done, there is a certain predictability to the result. Add this to the growing list of papers showing that a personality/psychological/economic trait has heritability of between 0.2 and 0.4. It’s also another example of twin studies being more useful than the molecular biology.

When I asked for suggestions for my evolutionary biology and economics reading list earlier this year, Boyd and Richerson’s The Origin and Evolution of Cultures was one of the most recommended. Their exploration of cultural evolution has many elements that are relevant to economics, including the development of institutional frameworks, the evolution of cooperation and the transmission of technology.

The book comprises 20 papers (published between 1987 and 2003) that are grouped into five thematic groups: the evolution of social learning; ethnic groups and markers; human cooperation, reciprocity and group selection; archaeology and culture history; and links to other disciplines. Each chapter was a stand-alone paper, so rather than going into any of them in further detail, I will save that for some later posts and give some more general observations here.

First, Boyd and Richerson are clear in arguing that “culture” is a distinct feature from “environment”, and that it should be examined through an evolutionary lens:

[C]ultural variation is transmitted from individual to individual, it is subject to population dynamic processes analogous to those that effect genetic variation and quite unlike the processes that govern other environmental effects. Combining cultural and environmental effects into a single category conceals these important differences.

Having been sceptical before reading the book, this is one issue on which I am a convert. I am still not convinced that it is always (or often) possible to identify practically which cultural trait is subject to selection or to differentiate it from the environment, but drawing this distinction led to some interesting and parsimonious models. Further, an evolving cultural trait may be the environment for another cultural trait.

Their exploration of cultural evolution often contains a genetic element, usually in the context of “gene-culture coevolution”. For example, they describe a process whereby cultural institutions might result in people with certain genetic predispositions beings weeded out.

Mechanisms by which cultural institutions might exert forces tugging in this direction are not far to seek. People are likely to discriminate against genotypes that are incapable of conforming to cultural norms (Richerson and Boyd, 1989; Laland, Kumm, and Feldman, 1995). People who cannot control their self-serving aggression ended up exiled or executed in small-scale societies and imprisoned in contemporary ones. People whose social skills embarrass their families will have a hard time attracting mates. Of course, selfish and nepotistic impulses were never entirely suppressed; our genetically transmitted evolved psychology shapes human cultures, and, as a result, cultural adaptations often still serve the ancient imperatives of inclusive genetic fitness. However, cultural evolution also creates new selective environments that build cultural imperatives into our genes.

However, Boyd and Richerson’s exploration of gene-culture coevolution does not usually extend to developing models with where genes and culture simultaneously evolve. At times this is problematic, particularly where they incorporate cultural group selection into the picture, as it can be difficult to understand how the process would actually work from the often loose verbal descriptions. Conversely, a model incorporating these multiple evolving elements would lose the clarity and simplicity that allows most of the models in the book to be useful.

The indeterminate nature of the culture-environment distinction I alluded to above is also highlighted by this gene-culture evolution quote. Cultural evolution creates new selective environments. While a cultural trait is evolving, it is effectively creating an environment in which other cultural traits or genes evolve. This is similar to the idea that genes effectively create the environment in which other genes evolve, whether those other genes be in the same individual or in other individuals and species.

Boyd and Richerson’s work shares some similarity with that of Sam Bowles and Herb Gintis, particularly in their approach to model development. Simulations are used as illustrations, the focus is more on demonstrating ideas than providing hard proofs, and agent based models are a common tool.  However, Boyd and Richerson have a stronger sense than Bowles and Gintis of the limitations of their models, and generally recognise their illustrative and not determinative nature. Bowles and Gintis have a habit of making a model and arguing that, since a certain feature didn’t work in their model (such as the evolution of cooperation by reciprocal altruism), their model is evidence that it can’t work at all. The problem with this approach is that the model only examines such a small subspace of the possibilities. Boyd and Richerson tend to be more constrained in their conclusions, although not always so.

One of the groups of papers focuses on group selection. I am more open to analysing the transmission of cultural traits through the lens of group selection (or multilevel selection) than I am for the transmission of genes, largely because cultural group selection is not necessarily undermined by migration between groups in the same way as genetic group selection. Boyd and Richerson note this when they state:

[S]ocial extinction does not mean physical elimination of the entire group. Quite the contrary, most people survive defeat but flee as refugees to other groups, into which they are incorporated. This sort of extinction cannot support genetic group selection because so many of the defeated survive and because they would tend to carry their unsuccessful genes into successful groups, rapidly running down variation between groups. However, the effects of conformist cultural transmission combined with moralistic punishment makes between-group cultural variation much less subject to erosion by migration and within-group success of uncooperative strategies than is true in the case of acultural organisms.

However, I am still not convinced that the cultural group selection approach provides the clearest method of analysis. I’ll save my specific issues with their approach in a separate post.

My favourite chapter of the book was the least theoretical. Boyd and Richerson (with Joseph Soltis) asked whether observed rates of group extinction could be sufficient for group selection to drive rapid cultural evolution. Based on an examination of hunter-gather tribe extinction rates, they concluded that group selection could not be responsible. It was refreshing to see some empirical analysis applied to this issue. For all the noise around group selection (both genetic and cultural), it is rare that the debates are accompanied by increasingly available data.

*My later post with my thoughts on their approach to group selection can be found here.

An article by Josh Fischman in the Chronicle suggests that economists have been slow to take up the insights of neuroeconomics.

Paul W. Glimcher, director of the Center for Neuroeconomics at New York University and author of the standard textbook in the field, wrote in a 2004 paper published in Science that “economics, psychology, and neuroscience are converging today into a single, unified discipline.” Today he is more measured. “We are a very young science,” he says, “and we’ve taken more from economics than we’ve given. I hope in the coming years you’ll start to see us give more back.”

And economics does need some help, according to a few practitioners like the eminent Yale University economist Robert J. Shiller, who has argued that the discipline isn’t doing just fine. Most economic models didn’t predict the 2008 housing crash, he pointed out in a speech at last year’s Society of Neuroscience meeting. Adding some understanding of how the brain reacts to particular kinds of uncertainties or ambiguities in supply and demand, he said, might avoid this and other costly misfires.

The slow take-up of neuroeconomics in the short-term by the broader economics profession is not a bad thing. Neuroeconomics is often seeking to build on and test findings from behavioural economics, but the findings from neuroeconomics are not yet fundamentally changing the understanding of human behaviour that behavioural economics gives us. Take the first example used Fischman:

One recent study, published this summer, searched for brain regions associated with altruism and selfishness. Ernst Fehr, a professor of economics at the University of Zurich, and one of the few economists working extensively with neuroscientists, asked a group of 30 men and women to split a sum of money with another person or keep more for themselves. While each person was making the decision, Fehr’s team took images of his or her brain in a functional-magnetic-resonance-imaging machine. The fMRI scanner reveals fine details of brain anatomy and, crucially, measures how active brain regions are. It has become a standard tool in this field.

Those people who were willing to split more money had more neurons in a region called the right temporo-parietal junction, an area toward the back of the brain that has been linked to empathy. Selfish people had a smaller junction. Moreover, the junction became more active as unselfish people decided to give more money away, Fehr and his colleagues found. It is almost as if the region worked hardest when people were trying to overcome what might be a natural—and rational—impulse toward selfishness.

The finding is interesting, but how would an economist incorporate this into their understanding of human action beyond that already provided by behavioural economics? The concept of competing brain structures in decision-making is common in psychology and evolutionary biology – or even economics. Pinning down a location in the brain (and trying to give it an interpretation) is not substantively changing this.

In some ways, neuroeconomics is in a similar state of development as genoeconomics, the use of molecular biology in economics (also referred to in Fischman’s article). Genoeconomics is seeking to build on the understanding of human behaviour that we can get from evolutionary biology. But genoeconomics is at such an early stage that it is not fundamentally changing this understanding. An economist seeking to incorporate evolutionary biology into their economic thinking can use evolutionary theory, twin studies and anthropological studies, after which they will gain limited additional understanding from genoeconomics.

However, this points to the real problem. The areas that neuroeconomics and genoeconomics are building on, behavioural economics and evolutionary biology, could and should be used to a greater extent in economics. Economists don’t need to wait for more information on which region of the brain or which gene underlies a behaviour before incorporating it into a model. Behavioural economics is a mature field (albeit one lacking a framework – that evolutionary biology will one day offer) and our knowledge of human evolution and the heritability of traits gives great scope for evolutionary biology to be used.

Having said this, we should not ignore neuroeconomics and genoeconomics. The findings being developed today have value. I wish more research was being conducted in these areas and that economists were more involved. Colin Camerer notes the lack of economists involved in this research:

“I would say that neuroeconomics is about 90 percent neuroscience and 10 percent economists,” says Colin F. Camerer, a professor of behavioral finance and economics at the California Institute of Technology and one of the prime movers in the new field. “We’ve taken a lot of mathematical models from economics to help describe what we see happening in the brain. But economists have been a lot slower to use any of our ideas.” …

Camerer, who was trained in economics—he got an M.B.A. and a Ph.D. from the University of Chicago and “didn’t know anything about neuroscience until 2000″—says that assuming that economics can’t be improved by knowing how the brain computes value might be the most unsound prediction of all. “That’s really kind of a crazy bet,” he says.

It is just this research is not at a point where it can revolutionise economic theory in the way its more developed relations can. Of course, this will change over the next decade as neuroeconomics and genoeconomics mature and researchers develop causative explanations that add to our knowledge of human behaviour. At that point, the complaints about the failure to adopt neuroeconomics and genoeconomics will have substance. Until then, the lack of evolutionary biology and behavioural economics in the practice of most economics is the bigger issue.

I’ve been working through Gary Becker’s A Treatise on the Family: Enlarged Edition over the last couple of weeks. One interesting section included Becker’s thoughts on why people demand their own children, as opposed to being satisfied with the children of others.

[T]he demand for own children, the distinguishing characteristic of families, need not be postulated but can be derived.

Women producing children can use their own milk as food and can more readily take care of young children while pregnant than while working in the marketplace. Moreover, most women have been reluctant to commit so much time, effort, emotion, and risk to producing children without considerable control over rearing. Presumably the genetic similarity between parents and children further increases the demand for own children.

Own children are preferred also because of the value of information about children when investing in them. Information is more readily available about the intrinsic characteristics of own than adopted children, because parents and own children have half their genes in common and the health and some other characteristics of own children at birth and during infancy are directly observed. … This may also explain why orphaned children of siblings and other close relatives are more frequently adopted than are orphaned children of strangers (Goody, 1976), and even why adopted children are less valued as marriage partners.

Becker introduces biological considerations at several points of the book, but this explanation of the demand for children is one of the more awkward. It’s not hard to see what would happen to those who overcome this information asymmetry to allow them to efficiently raise children that are not their own.