Zuk’s Paleofantasy

3 June 2013 by Leave a Comment

For some time, the “Paleo” lifestyle has been due for a decent critique from the perspective of growing evidence about the rapid rate of human evolution. Humans have evolved markedly since the dawn of agriculture, with adaptations ranging from disease resistance to the improved ability to digest starch. So when I heard of Marlene Zuk’s Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live, I was looking forward to that critique being provided.

And Zuk certainly provides a critique. She relentlessly pulls apart the ideas that we are well adapted to the Paleolithic environment, or that rapid environmental change means that there is mismatch between the environment and our genes. As Zuk points out, evolution does not result in stasis and there is no point at which we are ever completely adapted to our environment. We will always be a collection of bootstrapped responses to changing conditions.

However, Zuk’s critique was not the one I was hoping for. As was the case for the promotion pieces and reviews that I read before reaching the main course, Zuk parades a series of straw men rather than searching for the more sophisticated arguments of Paleo advocates. Many chapters begin with misspelled comments that Zuk found under blog posts. While Zuk shoots the fish in the barrel, the more interesting targets are not addressed.

In a Nature review, John Hawks suggests that Zuk’s use of the term ‘fantasy’ is a reference to hypothesis forming, where we play with hypotheses and try to falsify them. I tried to read the book in that light, but it is hard to do. Zuk appears so keen to throw Paleo-enthusiasts under the bus that she does not give many of the hypotheses the thought that they deserve.  At times Zuk seemed almost desperate to find someone to be on the other side of her debate, such as when she chose Ryan and Jetha’s Sex at Dawn as her punching bag for her discussion of sex differences, even though Ryan and Jetha are almost on their own with their thesis. Where she did write qualifiers about not everyone believing in the straw man that she was about to dispatch (which was often), she would proceed to torch the straw man as though the just acknowledged view did not exist.

Take the chapter on diet. Zuk points out that many humans have evolved lactose tolerance. Those with a longer history of agricultural diets have genetic adaptations to allow them to digest starch more efficiently. Even the foods we eat have evolved, with potatoes formerly bitter and lumpy, and corn having a shape and size more like a stalk of rice. But these are points most Paleo-advocates would happily concede. They are not seeking a historical re-enactment. Their argument is not that we have not changed at all, but that the changes have not been enough to make a diet full of grains and sugar superior to a diet of meat, nuts, fruit and vegetables. Whether that is the best diet could be the subject of an interesting debate (i.e. testing the hypothesis), but this is not the argument that Zuk engages with.

Moving to a more substantial point, a review in Evolutionary Psychology nicely summarises Zuk’s mismatch argument as being at three levels: there are no mismatches as all species are adapted to past environments, not current ones; even if mismatches occur, we are not in a position to understand them; and the mismatch perspective has not proven beneficial.

On the first of these, Zuk pushes too far by highlighting cases of rapid evolution while ignoring cases where mismatch does occur. Her description of the evolutionary bootstrapping that must occur when organisms encounter new environments points to the potential of mismatch. Zuk’s arguments about the difficulty in understanding mismatches leans towards saying it is all too hard, and not engaging in the sort of hypothesis testing that Hawks refers to. And on the point that the mismatch hypothesis has not proven useful, there are times where Zuk shows just how useful a mismatch perspective might be. She acknowledges that the high sugar content diet of the last 50 years is not something we are matched to, and provides some interesting points on barefoot running and the evidence of the cost of cushioned shoes. The mismatch between current and past physical activity (accompanied by the suggestion that people should simply “get off the couch”) is almost too obvious to mention.

Having said all the above, I still enjoyed the book. There is a lot of punchy writing, many important research results and underneath her advocacy style, some interesting questions about diet, exercise and other “Paleo” lifestyle features. However, my instinct is that many people won’t see these points due to Zuk’s approach, which will lead to a less interesting debate than we could have had. I suppose this post is further evidence of that.

*To avoid getting completely derailed by style instead of substance, next week I’ll write a post on what I consider to be the most interesting questions about recent evolution and the Paleo lifestyle.

Filed Under: Economics, Evolution Tagged With: , , , ,

Hwang and Horowitt’s The Rainforest

30 April 2013 by Leave a Comment

A couple of months ago I linked to a piece by Ronald Coase about the state of economics. Coase wrote:

Economics as currently presented in textbooks and taught in the classroom does not have much to do with business management, and still less with entrepreneurship. The degree to which economics is isolated from the ordinary business of life is extraordinary and unfortunate.

As readers of this blog would know, most of what I read and write is relatively isolated from ordinary business life. But reading a book such as Victor Hwang and Greg Horowitt’s The Rainforest: The Secret to Building the Next Silicon Valley shows that the topic of this blog can be relevant to the business world.

The world dealt with in The Rainforest is innovation ecosystems of the type that we see in Silicon Valley. Why is Silicon Valley such an innovative place, and why do most attempts to create new Silicon Valleys around the world usually end in failure?

To answer this, Hwang and Horowitt turn to a biological metaphor – the rainforest. In a “rainforest”, innovators are able to tinker and engage in trial and error to discover the most efficient ways of combining capital, talent and ideas. This provides for an evolutionary – not engineered – process, where new innovations can emerge.

Hwang and Horowitt argue that to understand a rainforest, we need to understand something of biology, psychology, neuroscience and sociology. Some of the background materials that I had read on the book, such as Victor Hwang’s blog at Forbes, pointed to E.O. Wilson’s recent forays into group selection. However, when you get into the book, it’s ideas from the Wilson of pre-2005 that dominate. And although not explicitly named, the fingerprints of the likes of Robert Trivers are also present.

Hwang and Horowitt described many elements of a successful rainforest, but the one that stood out for me was trust. When trust is high, transaction costs are low (Coase also plays a fairly prominent role) and people can easily enter into new engagements. Lawyers are not required to draft terms and the entrepreneur is willing to share their ideas without fear of them being stolen.

So why does this trust exist? In part, it is because there is a strong normative culture with punishment against defectors. Take a transaction between an entrepreneur and a venture capitalist. In a single transaction, there might be opportunity for the venture capitalist to take as much of a stake in the company as they can. However, with strong norms about what a fair agreement looks like and a willingness to punish those who push for unfair terms, that venture capitalist’s reputation will spread quickly and their one-off gain turns into a long-term loss. Trust is also supported by a strong culture of reciprocation (hence my reference to Trivers above).

While Wilson’s group selection gets mentioned, the rationale given by Hwang and Horowitt for the forming of cooperative groups is generally rooted in the strong individual advantages. They relate the example of people moving to the Western frontier in the early days of settlement in the United States. Despite a reputation as a period of rugged individualism, almost no-one embarked on the journey alone. The personal benefits to cooperation were vital. In the same way, to succeed in an innovative ecosystem, a person needs to be be connected to a broad variety of people. One of the primary ways of measuring the health of the rainforest is to look at those connections and the flows that occur along them.

The question that these types of explanations naturally draw out is how this culture exists in the first place. As Hwang and Horowitt point out, while people are naturally groupish, we distrust people dissimilar from ourselves and will generally act in our self interest. Places like Silicon Valley are particularly diverse, so we might expect them to be relatively atomised.

One reason is what they call extra-rational motivations. People are not purely self-interested in a money sense, but also seek adventure, interest, membership of groups and the like. Embarking on a start-up venture has pay-offs beyond the financial. They pick on neoclassical economists for ignoring these motivations, but I think this is more a case of ignorance in the models than ignorance that they exist. These motivations mean that people are willing to cooperate and enter into new ventures for the non-monetary benefits that they receive.

A second answer that they hint at is the self selection of the people in places such as Silicon Valley. I suspect this is where much of the answer lies, because apart from their wish to be entrepreneurs, one of the selected characteristics are high levels of intelligence, which is in turn correlated with trust (both trusting and trustworthiness). In a community where most people are trusting and trustworthy, and people are willing to punish the occasional defectors (even if that is by simply never dealing with them again), cooperation can be expected to be highly beneficial and will flourish. Hwang and Horowitt return to the self-selection issue at the end of the book when they suggest that the people now moving to Silicon Valley have different characteristics to those who create the innovative culture. They suggest that new arrivals who are more interested in employment than entrepreneurship may change the culture. I also wonder in what other characteristics they differ?

Hwang and Horowitt are regularly engaged to support the establishment of innovative ecosystems in various countries and parts of the world. An interesting experiment would be to run experimental games such as the prisoner’s dilemma and public goods game with the groups whom the authors work and see what the results are. Are the results of these games predictive of whether a vibrant innovative ecosystem will be established? Does the level of cooperation in these games increase in successful environments?

There are plenty of other interesting ideas in the book, although I’m still to be convinced about the degree of control we can have when trying to create these types of innovative ecosystems. I probably need to see it to believe it. Still, it is nice to see ideas that I often talk about abstractly, such as  reciprocation, altruism and trust, being used in some practical analysis.

Filed Under: Economics, Evolution Tagged With: , , , ,

Flynn’s Are We Getting Smarter?

25 February 2013 by 1 Comment

James Flynn of Flynn effect fame has a relatively new book out, Are We Getting Smarter? I have found Flynn’s earlier books to be easy but not great reads, and this book followed that pattern. However, reading them is worthwhile as they tend to provide a comprehensive update on the latest in IQ testing from around the globe. Flynn is also not afraid to throw in some interesting arguments.

The question in the title of the book has two elements. First, does the Flynn effect mean that we are getting smarter? Flynn prefers to say that we are not necessarily smarter, but that we are more modern. We are born with the same mental hardware, but in a more complex world humans are becoming more “scientific” in their thinking. We are better able to characterise and abstract.

The second is whether this trend is continuing, and generally it is. Except for the Scandinavian countries, IQ is still going up in the United States, England, Germany and other developed countries. IQ is also increasing at a slightly faster rate in developing countries, but not fast enough to close the gap with developed countries in the near future. There are also some notable exceptions, such as Sudan.

One of the more interesting chapters is Flynn’s discussion of IQ testing of death row inmates. If an inmate has a tested IQ of 65 or below, they are spared execution. But consider two inmates of the same intelligence who were both tested for intelligence in 1975, but one was tested using a 1972 normed test, while the other completed a test normed in 1947-48 (tests need to be normed regularly because of the Flynn effect). Given the different dates on which the tests were normed, the former can have their IQ measured at 65 and be spared, while the latter would be measured at 73 and face the death penalty. The view of courts on this point appears mixed. More broadly, however, it hints at an important discipline in considering IQ test results. If you are confronted with an IQ test result, you should ask when was the test normed and when was the test taken. It is only in that context that the result can be meaningful.

Flynn spends some time revisiting old debates with Arthur Jensen about whether the Flynn effect is measuring anything meaningful. In particular, Flynn accuses Jensen of psychometric obsessions by only caring about whether the Flynn effect is relevant to g, and not about whether there are any real world implications.

The relative cognitive complexity of the tasks (or their relative g-loadings) is beside the point. If you do not care about anything but finding an absolute measure of our ability to deal with cognitive complexity, an absolute measure of intelligence if you will, you will not be interested. Since you cannot correlate IQ gains with g, you dismiss them as “hollow” (Jensen, 1998). But that is only because you have been blinded to social significance by psychometric obsessions.

Despite their disagreements, however, Flynn credits Jensen with triggering his interest in the area, and dedicates the book to him. Flynn writes:

Psychologists should thank Jensen for pursuing his life-long mission, against great odds, to clarify the concept of g. In addition to intellectual eminence, he had the courage to face down opposition often political rather than scientific. If I have made a significant contribution to the literature, virtually every endeavor was in response to a problem set by Arthur Jensen.

The book also contains come interesting ideas about of the growing gap in language between parents and children (the problem teenage years) and the rise of single motherhood among black women in the absence of eligible men. Flynn also explores what he calls the bright tax and bright bonus – the relatively steeper decline in analytical ability but slower decline in verbal ability as those of high intelligence age (which I have posted about before).

Filed Under: Economics, Evolution Tagged With: , , ,

The best books I read in 2012

28 December 2012 by 1 Comment

As is normally the case, my annual list comprises the best books I have read in the past year, irrespective of their date of release. I read fewer books this year than usual, so I’m drawing from a smaller pool than for the last couple of years (2010 and 2011). Here are my favourite six for 2012:

Passions Within Reason: The Strategic Role of the Emotions by Robert Frank (my review): A book I should have read a long time ago. I particularly appreciated Frank’s use of path-dependent evolution to develop his model of human behaviour.

The Righteous Mind: Why Good People Are Divided by Politics and Religion by Jonathan Haidt (my review): At the top of many lists for good reason.

Adapt: Why Success Always Starts with Failure by Tim Harford (my review): Apart from being interesting and full of reasonable advice, Harford demonstrates a deep understanding of evolutionary processes, which is not often the case in books of this nature.

Thinking, Fast and Slow by Daniel Kahneman (my review): Magnificent. The clear and accessible way that each chapter illustrates a bias or heuristic makes it the best book on rationality and decision-making that I have read.

Moby Dick by Herman Melville: The best classic I read this year. Although I could have skipped some of the detours, many are fascinating.

Darwinian Politics: The Evolutionary Origin of Freedom by Paul Rubin (my review): A strong argument for political institutions that maximise freedom.

There are a few books that I read this year that have me in two minds, so I haven’t included them in the above list. I enjoyed Ridley’s The Rational Optimist: How Prosperity Evolves  (my review), but despite his claims to the contrary, Ridley stretched the evolutionary metaphor too far in drawing a Panglossian case. Robert Trivers’s The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life (my review) would have required a much more thorough editing to make this list. I also enjoyed Kevin Kelly’s What Technology Wants (my review), despite not buying the central argument.

Of the books I have in my reading pile, I still haven’t got to Pinker’s The Better Angels of Our Nature: Why Violence Has Declined, and I intend to read Flynn’s Are We Getting Smarter?: Rising IQ in the Twenty-First Century over the Christmas break. Hopefully they will crack next year’s list.

Filed Under: Economics, Evolution Tagged With:

Boyd and Richerson’s group selection

26 November 2012 by 4 Comments

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”.

Filed Under: Evolution Tagged With: ,

Boyd and Richerson’s The Origin and Evolution of Cultures

5 November 2012 by Leave a Comment

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.

Filed Under: Economics, Evolution Tagged With: , , , ,

Haidt’s group selection

28 September 2012 by Leave a Comment

Having given my thoughts on Haidt’s generally excellent The Righteous Mind in my last post, I want to turn to Haidt’s use of group selection in the last third of his book. The central themes of his book don’t rest on group selection (in my opinion), but Haidt is at the centre of the reemergence of group selection in the social sciences and his points are worth discussing.

Haidt uses the more modern language of “multilevel selection” in addition to “group selection” through the book. The first refers to a method of accounting for selection at the different levels (e.g. the gene, individual, group etc.), while the older concept of group selection usually refers to selection between groups and the evolution of group-level adaptations. Multilevel selection also involves trait groups, which may briefly form and break up, compared to the rigid reproducing groups of the old group selection.

It seems that Haidt has a reasonable grasp on these distinctions but his use of the term multilevel selection is often confusing. For example, he keeps using the phrase “product of multilevel selection”, but multilevel selection is, as the name suggests, selection at different levels. You can look at a scenario through a multilevel selection framework and conclude that all the selection occurs at the level of the gene or individual. Multilevel selection and inclusive fitness are just different accounting methods (or languages). It is not a case that one happens and the other doesn’t. What Haidt is implying, and the way the language should be used, is that selection is occurring predominantly at the level of the group. Based on some passages of the book, it is clear that Haidt understands this, but at other times his language is loose.

When Haidt argues for the importance of selection at the level of the group (I’ll refer to it as group selection for rest of this post), he offers four lines of evidence: the role of group selection in the major evolutionary transitions; the shared intentionality of humans; gene-culture evolution; and the potential for fast evolution.

The major evolutionary transitions, such as the emergence of eukaryotic cells from the combination of bacteria, are one of the few areas where many evolutionary biologists will agree that group selection occurred. Haidt characterises the major evolutionary transitions as times where methods to control freeriding evolved at one level, allowing superorganisms to arise at the next. Haidt then follows in the footsteps of biologists such as David Sloan Wilson and E. O. Wilson and argues that the evolution of “ultrasociality” in humans is a similar transition.

I don’t want to rehash this argument in-depth, but it goes back to the classic group selection debate. In the evolutionary transitions of the past, a reproductive bottleneck was present. Once two bacteria are combined in a cell, the only way they can reproduce is if the “group” reproduces. But that bottleneck does not exist in human groups, so there is opportunity for freeriding. We then get to the old debate about the level of freeriding and whether the level of group extinction and the degree of gene flow between groups allows group selection to outweigh this freeriding.

While Haidt follows in others’ footsteps in referring to the major evolutionary transitions, his other arguments are more his own. On shared intentionality, Haidt argues that the ability to share intentions between people allows collaboration, the division of labour and shared norms. While Haidt claims this is group selection, this is a case where the multilevel selection framework should be properly applied. How much benefit does one get as an individual from understanding what someone else is thinking, versus the benefit you get from pairing with someone who also has that ability and working together to succeed as a group? While having more people in your group who are able to share intentions will help you defeat other groups, shared intentionality is clearly beneficial to an individual. Being in a group of mind readers when you have no idea what is going on is suboptimal. Which level the selection predominantly operates at needs to be analysed (and will depend upon assumptions about what makes up a group). This is the type of scenario that I have argued before is simpler to analyse in an inclusive fitness framework.

Haidt’s third line of evidence is a somewhat confusing take on gene-culture evolution. Haidt argues that cultural group selection supported “prototribalism”, which led to an environment that then supported genetic evolution. However, Haidt’s examples do not sound like group selection. For example, Haidt writes:

[I]ndividuals who found it harder to play along, to restrain their antisocial impulses, and to conform to the most important collective norms would not have been anyone’s top choice when it came time to choose partners for hunting, foraging, or mating. In particular, people who were violent would have been shunned, punished, or in extreme cases killed.

This sounds like individual level selection against violent, non-conformist individuals. I am not sure why Haidt was so keen to covert Boyd and Richerson’s arguments on cultural group selection into genetic group selection, but try he did.

Haidt’s biggest reach, however, comes with his argument that the potential for fast evolution supports group selection. Haidt notes that gene-culture evolution reached fever pitch in the last 12,000 years, and that is an assessment I would agree with. He refers to the group selection experiments conducted by William Muir, in which Muir rapidly improved egg laying by selecting groups of successful chickens (achieved, of course, through the effective creation of a reproductive bottleneck in the experimental design). Haidt then pushes the rapid evolution argument to the limits when he seeks to implicate group selection in the emergence of religion. As large-scale religion only emerged since the dawn of agriculture, Haidt suggests the rapid recent evolution identified by the likes of John Hawks, Greg Cochrane and Henry Harpending provides scope for recent group selection. He writes:

[G]roup selection can work very quickly (as in the case of those group-selected hens that became more peaceful in just a few generations). Ten thousand years is plenty of time for gene-culture coevolution, including some genetic changes, to have occurred. And 50,000 years is more than plenty of time for genes, brains, groups, and religions to have coevolved into a very tight embrace.

The problem is that group extinction and reproduction generally occurs more slowly than individual level selection. At the individual level, we see large differences in fertility every generation. For many people, it is the end of the genetic line. To the extent heritable traits underlie this variation, we can see rapid changes in genotype. In contrast, studies of rates of group extinction suggest it is slow. Further, groups tend not to be simply wiped out, but the “loser” groups tend to merge into the victor, bringing their genes with them.

Having said all this, we might be able to build a multilevel selection model in which we allow temporary religious or other “trait groups” to form and break up in short periods and divide the degree of selection between the various levels. However, I still doubt we will see significant selection at the group level for most of these examples and I don’t feel that this was the sort of group selection Haidt was interested in. Further, I expect the inclusive fitness framework would give a clearer picture. If this trait group approach could have provided a stronger argument, Haidt might have used it.

Filed Under: Evolution Tagged With: , , , ,

Haidt’s The Righteous Mind

26 September 2012 by 4 Comments

I am going to give my thoughts on Jonathan Haidt’s The Righteous Mind: Why Good People Are Divided by Politics and Religion over two posts as I want to split the good from the bad. The first two-thirds and the close of the book are excellent. However, slotted in the last third is Haidt’s take on group selection. His group selection argument deserves attention, but I don’t want to derail this post with a group selection critique, particularly when Haidt’s broader arguments do not rest on it.

Haidt’s goal is to explain why people are divided by politics and religion. He has three major explanations for this division: we are primarily guided by our intuitions (not reason); there’s more to morality than harm or fairness; and morality binds and blinds.

Part 1 of the book is based on the concept that intuition comes first, strategic reasoning comes second. When presented with a new situation, we tend not to reason to our moral response. Rather, our instincts offer a moral response, and we then use our power of reasoning to justify it. Haidt asks us to picture our reasoning as a rider on an intuitive elephant. The elephant leans in response to a situation, and the rider rationalises why they are going in that direction. It takes a real effort to turn the elephant.

Much of the material through this section is fodder of popular accounts of decision-making, ranging from material on confirmation bias to Phillip Tetlock’s work. Haidt’s elephant and the rider also draws comparisons with Daniel Kahneman’s System 1 and System 2. However, the application of this framework to moral psychology is interesting, particularly as the nature of the elephant changes between people – as Haidt highlights in Part 2.

Haidt starts Part 2 with a story about an experiment in which he exposes a subject to a novel moral dilemma and makes them justify their moral judgement. One story involves a man who buys a chicken from the supermarket (already dead) and has sex with it before he cooks and eats it. As no-one is harmed, someone rationalizing the story under the scrutiny of an interviewer might ultimately decide that there was no moral transgression. When Haidt moved beyond his usual WEIRD (Western, educated, industrialised, rich and democratic) experimental subjects to people entering a suburban McDonald’s, he found that there was astonishment at the interviewer’s questions as to whether the action was wrong. Why do you even need to ask? From this picture, Haidt argues that there is more to morality than fairness and harm, the staples of liberal morality (liberal in the sense it is used in the United States – and how I will use it for the rest of this post). There are six foundations to morality – care/harm, liberty/oppression, fairness/cheating, loyalty/betrayal, authority/subversion, and sanctity/degradation.  An extra wrinkle is that fairness contains equality and proportionality elements.

Liberal morality tends to rest on the care/harm and to a lesser extent on the fairness/cheating (equality) and liberty/oppression dimensions. Conservative morality tends to rely on all six, with an emphasis on proportionality for the fairness/cheating dimension.  The libertarian moral framework rests almost entirely on the liberty/oppression dimension (with a small dose of fairness/cheating thrown in). Haidt suggests that this gives conservatives the edge in understanding the concerns of the full political spectrum. It is not that conservatives don’t care about harm. They simply weight it differently. When conservatives and liberals undertake an ideological Turing test, where they had to answer questions as though they were the other, conservatives and moderates do better than liberals. Haidt does not delve into the consequences of the narrow libertarian moral foundations in detail, but it raises the question of libertarian’s ability to understand and communicate with other audiences.

The moral framework test at YourMorals.org that informs much of Haidt’s book suggests that I have a liberal framework, although with more weighting to proportionality than equality in the fairness/cheating dimension and a stronger tendency towards liberty (my scores are the green bars). I lean libertarian, but this is more due to my beliefs about how to reduce harm than a foundation built on freedom from interference, so the assessment may make sense (and is probably why I have more sympathy for the bleeding heart libertarians).

Haidt applies little substantive judgement to the merit of these moral foundations. In the conclusion, he supports moral pluralism, not relativism – but you get little of that flavor in the rest of the book. In part, Haidt’s swing towards conservatism makes him less inclined to critique any of the conservative foundations. However, as a description of moral frameworks, the discussion is excellent.

In Part 3, Haidt notes the grouping instincts of humans. In times of crisis, such as after 9/11, people act less selfish and pull together as a group. This groupish behaviour can act as a barrier to understanding others and is parochial, but Haidt argues that there are ways to increase group cohesiveness in ways that are not necessarily harmful to outgroups. We should be looking for ways to trigger this cohesiveness.

To illustrate this, Haidt  dedicates a chapter to religion, the ultimate in groupish behaviour. He argues that religion is an evolved cultural trait, not a maladaptive meme, as religion binds people into groups, suppresses freeriding and supports cooperation (he even goes as far as putting religion into the group selection basket, but I will also save that issue for my later post).  It is not an argument that will win fans among the new atheists.

Haidt closes the book with some suggestions to answer the opening question of the book: “Can we all get along?” Haidt is slightly naive in his hope that understanding someone else’s moral foundation will reduce conflict, but some of his other throw away ideas, such as having the families of legislators live in the same neighbourhoods to build civility, are interesting – although as Haidt suggests, we might be too far gone for that. If nothing else, his framework might help meet Haidt’s initial goal of understanding conservative morality and allow the Democrats write some better speeches with broad appeal.

Filed Under: Economics, Evolution Tagged With: ,

Kelly’s What Technology Wants

19 September 2012 by 2 Comments

Technology wants increasing efficiency, opportunity, emergence, complexity, diversity, specialisation, ubiquity, freedom, mutualism, beauty, sentience, structure and evolvability. As Kevin Kelly argues in What Technology Wants, these are the same things that life wants. Technology extends evolution’s four billion year path.

Whether you buy Kelly’s central thesis or not (in general, I don’t) and if you ignore some of Kelly’s near-religious fervour (particularly in the opening and closing chapters), Kelly provides a strong argument that the growth in technology is primarily beneficial, with the major benefit being increased choice. Technology provides the basis for achievement. The technology of vibrating strings provided the opportunity for virtuoso violin players. The technology of film allowed cinematic talents to blossom. And consider the technologies of writing and mathematics.

Kelly is not blind to the potential negative effects of technology. Shipping technology allowed mass slavery. The chemical industry spawns toxins. All technologies have unintended consequences. But in response to those negative elements, Kelly argues that prohibition is pointless. Prohibitions don’t work, don’t last and when they are put in place, are usually gone in the next technological cycle. Rather, we should use new technologies to offer solutions to old technologies, and use our knowledge of the path of technology to understand how to control the negative consequences. When new technologies emerge, they should not be banned but rather tested and actively assessed. Where harms occur, they should be rectified and where problems emerge, the technology should be redirected. The path of technology is inevitable and we cannot stop it.

The inevitability of technology is a central plank of Kelly’s argument. If the clock of time was rewound and started again, even with  different initial conditions, we would still end up with a similar path of development and resulting inventions. Kelly points to the examples of similar inventions occurring independently on different continents, such as agriculture. He points to the more recent phenomenon of multiple inventors of the same invention, such as lightbulbs or calculus. These technologies are inevitable, as is the rough order that they appear, as one builds on the other.

Kelly builds on this argument of inevitability by pointing to the (widely disputed) inevitability of biological evolution. Convergent evolution is a similar phenomenon to concurrent invention. Eyes and lactose tolerance evolved on multiple occasions.

I am not convinced that Kelly’s examples of concurrent invention or convergent evolution provide a strong case of the inevitability of invention or evolution, primarily because we don’t know what the fitness landscape of these technologies or traits looks like. If there is a single, clear peak for fitness, all paths will converge to it. If there is a complex multi-modal fitness landscape with a complex topography, we won’t see many of the possibilities. Within our own little world we will see convergence to a local peak, giving the impression of inevitability, but we might be missing the big picture. There may be an array of possibilities that we cannot get to.

Another issue is that we can find examples of one-off inventions or evolutionary solutions. As pointed out in a review by Jerry Coyne, the wheel only appeared in North America when brought by Eurasians. Similarly, bones, feathers and the human brain have only appeared once. How different would Africa or Australia’s path have been, and for how long, if they had been isolated from industrialising Europe?

I lean towards the view that biology is not repeatable . Small chance events have large effects. Although I am open to the idea that intelligence might be likely to evolve, a one-off example in over 4 billion years is hardly a strong case and doesn’t provide very many sample points.

If you pull that theoretical pin out of What Technology Wants, the argument that technology has direction lacks a solid thesis. As Matt Ridley did in The Rational Optimist, Kelly takes a general direction and tries to use evolution to turn it into an iron law. But it is the wrong tool to do so.

Regardless, I enjoyed the book greatly. It is full of interesting observations and ideas by an astute observer of technology. Just don’t look to it for the all encompassing theory of technology.

Filed Under: Economics, Evolution Tagged With: , , ,

Ormerod’s Why Most Things Fail

28 July 2012 by Leave a Comment

After sitting on my reading list for a few years, I have finally read Paul Ormerod’s Why Most Things Fail. Ormerod’s basic argument is that failure is all around us and given the complexity of the world, there are limits to how much corporations can control their fate or governments can control the success of their policies. Governments, firms and households lack complete information. They do not have the cognitive power to process the available information to determine the optimal choice. As a result, when you look at their success, the outcomes look more like the result of chance than of rational strategic decisions.

Ormerod’s argument is built upon some interesting work done by himself and others in which the extinction rate of United States firms (and ultimately a wider suite of global firms) was examined. Firm death tends to follow a power law distribution, and when mapped against the historical extinction of species, which we know is built upon chance events, the pattern looks similar. In models of firm extinction involving networks of interconnected firms, if firms are given much more than 10 per cent of the available information about their relationships with other firms and are able to affect those relationships, the patterns of firm death cease to mirror those which we see. This suggests that firms act with little control over their success or failure.

While this is an interesting argument and I would suggest an important observation, is the mapping of firms to species the right mapping for the analogy? For example, a species is defined (roughly) as a group of organisms that are capable of interbreeding and producing viable offspring. Thus, the units of selection, the genes, are limited to within that species. In the case of a firm, if we consider the unit of selection to be a strategy, these are able to spread to any firm. All firms are capable of interbreeding and producing fertile offspring. So are firms more akin to members of a species than to each being a species on their own? And if so, what implications does this have for the model? If individual organisms within species have similar patterns of death without reproduction to that observed for the extinction of species (which I expect is roughly the case), then the implications may be small. However, without exploring these types of questions, Ormerod was some way from having me fully convinced that his comparison is the right one.

Ormerod takes some time to build to his exploration of firm extinction and some detours of varying interest along the way. One of his building blocks is an exploration of Schelling’s models of segregation, which Ormerod uses to show that simple rules can result in surprising and complex phenomena. This example forms ones of the pillars of Ormerod’s case about the complexity of the world, but I wondered at times if this was the most convincing example available. Despite the complex behaviour in Schelling’s models and the difficulty of predicting which person will end up living where, the model does allow some prediction at the macro level. It is also the case for other models explored in this area, whether that being the first-order difference equations investigated by Robert May or Brian Arthur’s El Farol bar. Predicting specific results is near impossible, but picking the pattern and the effect of parameter changes on that pattern is possible.

The detours also includes some bashing of the neoclassical economics straw man, which rarely moves beyond attacks on the most basic of assumptions. Ormerod’s choice of supporting evidence is interesting, but the omissions are often obvious. Take his quoting of Vernon Smith on the flaws with existing models of the operation of markets, but no mention of Smith’s experimental work which suggests how well markets seem to find an equilibrium despite the knowledge shortfalls and bounded rationality. Similarly, when discussing bounded rationality, Ormerod does not explore the success or failure of heuristics (Also strange was the crediting of bounded rationality to Akerlof and Stiglitz with no mention of Herbert Simon). Ormerod could still have made his case with a more in-depth discussion, and then it might have felt more convincing.

Ultimately, however, it was the closing that was most disappointing. Once Ormerod has established that companies have little control over their fate, and that the world is too complicated for governments to make decisions (both arguments I am sympathetic to), he then takes little effort to ask what this means. In the company case, it comes with a call to innovation and flexibility. But given that strategic choice has little to no effect on the probability of firm survival, as Ormerod told us, why will that particular approach work? Why is Ormerod’s suggestion immune to this problem? Compared to Tim Harford’s examination in Adapt (whether you agree Harford’s recommendations or not), Ormerod’s examination of the practical implications is very thin.

When it comes to government, again the questions left unanswered are more interesting than those addressed. If governments are likely to achieve success only by chance and cannot possibly achieve success through detailed planning, what should they do? We have a host of government interventions ranging from legislation to enable joint stock companies to protection of property rights that could be argued to be important in affecting our wellbeing. How would these be facilitated in a world where we otherwise throw up our hands in despair? Ormerod’s hints at some ideas but instead of exploring them, he sticks to blanket denouncements of governments acting as though Soviet Russia was a success. Fair enough, but it’s not a very deep argument and I sense the book sells Ormerod’s thoughts on this question short.

Filed Under: Economics, Evolution Tagged With: , , , ,

Frank’s Passions Within Reason

11 June 2012 by 1 Comment

Since reading Robert Frank’s The Darwin Economy, I have been working through his back catalogue. The original and innovative Passions Within Reason: The Strategic Role of the Emotions is the best of Frank’s books I have read so far.

Frank’s major proposal is that the emotions act as a commitment device. When a dispassionate calculation shows that it is better to cheat, the emotion of guilt can act as a constraint to the “rational” course of action. When a dispassionate calculation shows that it would be better not to incur the costs of punishing someone for cheating you, the emotion of anger acts as a constraint, and prompts you to punish them regardless of the personal cost to you. These emotional responses are particularly important where someone has a high discount rate and give a greater weight to present costs and benefits than those that come in the future.

These emotional traits are able to persist in an evolutionary setting as the “irrational” behaviour allows people to make credible commitments, which then allow them to gain the benefits of increased cooperation or protection from cheating. For example, if you can signal that you are trustworthy and your guilt will prevent you from cheating someone, you are more likely to be able to enter beneficial trades and cooperative arrangements. If someone knows you will get angry and attack them if they cheat you, even though it is not a rational thing to do in that particular instance, they are less likely to cheat you in the first place.

Frank deals well with two of the obvious attacks on this argument: why did such a convoluted way of undertaking these actions evolve; and what might prevent someone faking the emotion to prevent being cheated or so that they can enter into a trade where they can cheat?

On the first, Frank recognises that evolution does not come up with the perfect solution, but evolves responses to the environment over time. There is path dependence in the range of traits we have. In this case, the mix of high discount rates and emotional constraints to those discount rates were the solution that was found, and not the ability to rationally assess that the short-term costs are worth it for the sake of reputation. If humans are cognitively limited, the other option may not be feasible.

As an example of this path dependence (although possibly not an accurate example), consider the time before the formation of complex societies where there are repeated opportunities for mutually beneficial trade. Then, a high discount rate might have been generally appropriate, with those who cheated being favoured as they incurred no long-term costs when they did. However, when greater complexity of society arose, those with a constraint to their high discount rates did better as they were able to refrain from short-term cheating behaviour and develop reputations for fairness. Rather then tempering those high discount rates, which might still be important in some circumstances, the evolved response was emotions to constrain them in other circumstances. This story might not be true, but it creates a picture whereby opposing tendencies cancel each other out rather than a person evolving the perfect foresight necessary to consider the repeated interactions and how to act strategically.

For the second argument, the prevention of cheating, Frank relies on signalling theory. Frank argues that emotions are not easy to fake, which makes them reliable signals of someone’s intentions. If they could be easily copied, they would cease to be used as signals and the benefits to copying the emotion would disappear. It is the fact that they are hard to fake that leads to them being used as signals in the first place.

There are parts of this argument that trouble me, as the costs to faking emotions seem low. The costs exist, as work by Centorrino and colleagues demonstrates, but there are successful fakers of emotion. Many psychopaths can appear trustworthy despite their lack of trustworthiness. Possibly cheaters do not proliferate because the benefits to faking emotion are low, but if that is the case, why do we put such faith in these emotions as signals? Possibly cheaters are simply found out too often, so despite one successful cheat, their reputation ruins future opportunity. In that case, the signalling role is not as important as establishing reputation.

Regardless, Frank shows that it is possible for mixes of cheaters and honest people to emerge, with the frequency dependent selection ensuring that neither type disappears. If everyone is honest, there is no point signalling honesty or monitoring for cheating behaviour, so cheaters can thrive. If everyone cheats, the few honest people will spend great effort to seek each other out, and reap the benefits from specialisation and trade.

The book is not without its flaws, but given the strength of the fundamental ideas and the way Frank argues them, it feels like nitpicking to mention them. The only one I will note for the moment is that Frank does not give justice to rational behaviour, such as doing the right thing because people will find out. As experimental evidence shows, while humans can act in what seem to be non-self interested ways, people adapt to the probability of being caught cheating and the available rewards. Emotions are a commitment device, but in some cases, rational calculation can do the job. People with higher IQ are more trustworthy, yet I would argue they are not more emotional.

However, that is being pedantic about an excellent book. It is entertaining and interesting throughout. Twenty four years after release, it is still a must read.

Filed Under: Economics, Evolution Tagged With: , , , ,
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