In my previous post, I took an esteemed colleague to task for his statements about group selection. In this post I will do the same for his statements on a different subject–cultural evolution. Before continuing, I want to explain why I am zeroing in on Jerry Coyne. It is not because I have been driven insane by his tepid review of my new book The Neighborhood Project (tepid=lukewarm; Jerry likes parts of my book!). Neither do I have any personal animosity toward Jerry. We are colleagues who seldom see each other face to face and don’t even interact much professionally. Jerry sticks pretty close to his specialty of speciation in his academic publications and has little reason to cite my academic work (although I have written on speciation earlier in my career). And I have little reason to cite Jerry when I write about my own specialties of group selection and cultural evolution.
Therein lies the problem. When Jerry steps out of his role of practicing scientist and into his role of spokesman about evolution for the general public, it’s like Clark Kent transforming into Superman. Suddenly he’s an authority on every subject and rounding up the criminals who don’t agree with him left and right.
The temptation to act like Superman (or oracle, or priest–choose your metaphor) exists for any scientist who writes for the general public. Most of the safeguards that hold scientists accountable for their factual claims are removed, leaving them free to say whatever they please to an undiscerning public. Some resist the temptation but others succumb, often without knowing that they have succumbed.
This is a genuine dilemma with no easy solution. Writing about science for the general public is an important role in society, now more than ever. Writers who are not trained as scientists must be prepared to do a lot of homework. The best of them develop a professional level of knowledge to combine with their writing skills. Scientists must often struggle to become gifted writers. In addition, even scientists must do a lot of homework if they are going to write about topics outside of their own academic specialty. The fact that Jerry and I are both evolutionists doesn’t mean that I’m an authority on speciation or that he is an authority on group selection or cultural evolution. We would need to do our homework, no less than a journalist writing about the subject.
What happens when a scientist who writes for the general public doesn’t do his or her homework on a particular topic? Unlike an academic article, which would be quickly rejected by the peer review process, the piece written for the general public tends to be accepted on the strength of the scientist’s general reputation. So-and-so (insert Jerry Coyne, Richard Dawkins, Sarah Hrdy, P.Z. Myers, Joan Roughgarden, or myself) is a well-regarded scientist, so they must be telling the truth, or at least the closest that modern science has come to the truth.
Actually, not. The scientific process doesn’t work that way, and writing about science for the general public won’t either. The collection of cultural norms and practices loosely called the scientific method expects the individual scientist to be as conscientious and objective as possible, but also realizes that this is an impossible ideal, similar to the impossible Christian ideal of being as perfect as Jesus. That’s why an entire cultural system is required for science to exist, including the peer review system. Even then it’s a clunky process, like making laws and sausages, but it’s the best method we have for apprehending the real world. And make no mistake–there is a real world that we distort with our beliefs at our own peril.
Against this background, we can return to a particular scientist who writes for the general public, such as Jerry Coyne. When I criticize him for his statements on group selection or cultural evolution, I’m not being mean. I’m just acting in scientific mode and expecting him to do the same. If he tried to say in an academic article what he’s saying to the general public, it would never make it through the peer review process. He hasn’t done his homework. If I ever write something on speciation that needs to be corrected, I hope that Jerry will volunteer to set me straight.
Now to the subject at hand. Here is a thumbnail sketch of the current state of scientific knowledge about cultural evolution.
1) Darwin’s theory of evolution originally said nothing about genetics. It was framed in terms of heritability, which is a resemblance between parents and offspring. Any proximate mechanism that results in heritable variation enables organisms to adapt to their environments.
2) Genetics is the first inheritance system to be worked out in detail–so much detail that many people, professional evolutionists included, reflexively equate evolution with genetic evolution. There is no conceptual warrant for this assumption, however.
3) There is a long history of theorizing and research on evolution as a substrate-neutral process, based on the three fundamental ingredients of variation, selection, and heritability. What “substrate-neutral” means is that there can be many proximate mechanisms underlying heritable variation. Genetic algorithms in computer science provide an example.
4) An excellent recent book on this topic is Evolution in Four Dimensions, by Eva Jablonka and Marion Lamb. In clear language that any reader with sufficient interest can understand, they show how epigenetic mechanisms, learning, and symbolic thought count as inheritance systems, which interact with each other and with genetic inheritance. They also recount the history of why genetic inheritance became so dominant for the study of evolution that many people reflexively equate evolution with genetic evolution.
5) Non-genetic inheritance systems evolved by genetic evolution and have complex architectures insuring that the outcome of evolution is genetically adaptive, on average. For that matter, genetic inheritance has a complex architecture that evolved by genetic evolution, a topic that is often called “the evolution of evolvability” (type this phrase into Google Scholar for more).
6) The vertebrate immune system provides a model for understanding other inheritance systems that evolved by genetic evolution. On one hand, it is elaborately genetically innate, as anyone who has tried to learn immunology knows. On the other hand, it is elaborately open-ended, thanks to the capacity to generate app. 100 million antibodies and select those that successfully bind to antigens. We should be thinking of our capacity for open-ended individual and cultural change as like the immune system, which is a major theme of The Neighborhood Project and some of my academic articles.
7) B.F. Skinner described operant conditioning as a product of genetic evolution and itself an evolutionary process (see his classic paper titled “Selection by Consequences“). This part of behaviorism was on the right track, however much the tradition failed in other respects. Bizarrely (in retrospect), the brand of evolutionary psychology associated with Leda Cosmides and John Tooby set itself apart from the open-ended capacity for change associated with behaviorism. Creating a broader vision of evolutionary psychology is part of the serious work attempted in The Neighborhood Project and my related academic work.
8) The study of human cultural change as an evolutionary process has a long history that dates back to before Darwin–linguistic phylogenies existed before biological phylogenies. Some of the early conceptions were mistaken in retrospect, such as cultural evolution as a linear progression from “savages” to “civilization”. Dawkins’ concept of memes got some things right but other things wrong. The current state of play is represented by books such as the aforementioned Evolution in Four Dimensions, Not By Genes Alone: How Culture Transformed Human Evolution (by Pete Richerson and Rob Boyd), War and Peace and War (by Peter Turchin), and Sense and Nonsense: Evolutionary Perspectives on Human Behavior (by Kevin Laland and Gillian Brown). Although much remains to be discovered, the consensus view is that genes and culture have been co-evolving for a long time, so that the study of humans must be based on a firm foundation of biocultural evolution.
9) While individual learning and a degree of cross-generational social transmission takes place in many species, the human capacity for symbolic thought places us in a league of our own as far as cultural evolution is concerned. Symbolic systems have the same kind of combinatorial diversity as genetic systems–and every “symbotype” has a corresponding phenotype. The analogy between genetic evolution and cultural evolution is anything but superficial.
10) The subject of cultural evolution intersects with the subject of group selection in a number of ways. A major evolutionary transition was probably required for our capacity for symbolic thought to evolve in the first place. Given our current capacity, cultural evolution is a multilevel process, no less than genetic evolution. In other words, a cultural trait can spread by virtue of benefitting some individuals compared to others within groups, or by virtue of benefiting whole groups, compared to other groups. It can also spread without benefitting human individuals or groups, a legitimate possibility suggested by authors such as Richard Dawkins and Daniel Dennett. Most authors who contribute to the academic literature on cultural evolution accord a strong role for cultural group selection.
Against this background, what does Jerry have to say on the subject of cultural evolution? Beginning with his review of The Neighborhood Project:
Wilson further undermines his case by repeatedly counting as “evolutionary” any human activity involving “variation and selection”…But these issues have nothing to do with biological evolution: they are superficial and meaningless parallels with natural selection’s winnowing of genetic variation.
There goes Superman again, rounding up the criminals with his mighty powers. Jerry acts as if I am the outlier, when in fact it is Jerry who is excessively gene-centric and hasn’t done his homework.
The final chapter of Jerry’s book Why Evolution is True shows that he has a dichotomous view that sets “evolution”, “biology”, and “genes” apart from “culture”, “learning”, and “choosing our own destiny”. This view is common enough, but it fails to reflect developments during the last few decades, which place our open-ended capacity for change inside the orbit of evolutionary theory. Jerry’s views on cultural evolution are as outdated as his views on group selection.
There’s something else about Jerry. He repeatedly uses uncertainty in science as a call for inaction. That will be the subject of my next post.