The Social Genome: The New Science of Nature and Nurture by Dalton Conley
The Social Genome: The New Science of Nature and Nurture by Dalton Conley
Dalton Conley is a Professor of Sociology at Princeton University. With a BA in the Humanities from the University of California, Berkeley, an MPA in Public Policy, and a PhD in Sociology, both from Columbia University, Dalton spent many years investigating the causes of variation in health and socioeconomic status among humans, resulting in several books. Apparently, he was not entirely satisfied as he felt something was missing in his analysis. That something he realized was the role of genes. So, he returned to school to study genetics and got an MS and PhD in Genomics from New York University. Now, he seems a little more satisfied with his new analyses. These are brilliantly summarized in his latest book, The Social Genome.
Humans have always been interested in the role of genes in shaping human traits, including those concerned with behaviour and culture. While some role for genes is obvious, quantifying their contribution has been difficult and contentious. One of the reasons for this is that single genes rarely have isolated effects on complex human traits - most traits are polygenic. Conley discusses the so-called Polygenic Index (PGI) at great length. PGIs, which combine the effects of multiple genetic variants to compute the predisposition to develop any given trait, are the closest we have ever come to measuring the effects of genes on complex human traits. The predictive powers of PGI are already impressive, but this is just the beginning. PGIs are bound to improve significantly as more genomic data on more people becomes available. PGIs can be used for good or evil, like any new knowledge or technology. I think (and fear) both will happen. I learned much about PGI’s from The Social Genome, and much of it was new to me.
A particularly fascinating part of Conley’s book is his discussion of nature and nurture, with ‘and’ being the operative word here. The debate concerning the supremacy of nature (genes) versus nurture (environment) has raged over centuries, if not millennia. Admitting that both nature and nurture play a role was considered a compromise. Going a step further, the idea that traits are the product of interactions between nature and nurture and not the independent additive effects of both is the currently accepted idea. This nevertheless suggests that we can quantify the relative contributions of nature and nurture. However, Conley goes a (big) step further. Using the clever analogy of the Mobius strip, he convincingly argues that the effects of nature and nurture are so enmeshed that it is impossible to distinguish between their effects, let alone quantify them. Nature and nurture affect each other’s effects in a series of countless feedback loops that, at the end of the chain, are simply indistinguishable. The PGI’s themselves are the result of inseparable combinations of nature and nurture. So, the many debates arising from the nature versus nurture dichotomy can and should finally be laid to rest. It is good omen that Robinson et al (1) have called for a greater integration of animal and human studies to strengthen the “genomic case against genetic determinism”.
The central theme of this book, of course, is the idea of the social genome. Some of this I already knew but what impressed me most were Conley’s convincing arguments and examples of how the genes of others can have an even greater influence on you than your own genes – this is the essence of the social genome. In retrospect, it all makes sense. If genes have at least some influence on social traits, then when the traits of others influence your traits, it is equivalent to the genes of others influencing your traits. What is new is that now we can measure and understand these effects.
However, I find Conley’s claim that he is one of the founding members of the field of sociogenomics entirely unacceptable. He does not tell us who the other founders were and when and how it was founded. Besides, he (re)defines sociogenomics as “the application of genetic data to human behavior to gain a more complete picture of nature and nurture.” As far as I know, the term sociogenomics was first coined by Gene Robinson in 1999 in a prescient Perspectives article entitled “Integrative animal behaviour and sociogenomics” published in Trends in Ecology and Evolution, with the explicit statement he propose(s) to call integrative studies of the molecular genetics of social behaviour ‘sociogenomics’(2). This is not the first time I have encountered such reinventing the wheel or major terms, without crediting the original, but I have never understood why. Ignorance is hard to believe as an explanation. I think that an obsession with “novelty” at the expense of profundity and rigor in our present academic value system is at least partly to blame, although this is not to condone it.
While the previous paragraph was a criticism, this one is merely a diagnosis of shortcoming. Dalton Conley is a sociologist who turned to genes to perform a more complete analysis of human sociology, and it is not surprising and no criticism that he looks at the social genome from the lens of sociology. Indeed, he defines his sociogenomics as “the application of genetic data to human behaviour.” But this is, at best, an extremely narrow focus and, at worst, a fatally biased view. Even sociologists cannot ignore that genes of our parasites, for example, can influence our traits. More broadly, the social genome, as described by Conley, especially the idea that your genes can have a greater influence on me than my own genes, can profoundly enrich the so-called ‘gene’s eye view’ of evolution - first proposed by GC Williams(3), taken to greater intellectual and popular heights by Richard Dawkins in his The Selfish Gene(4), and masterfully historicized by Arvid Ågren(5). A reexamination of the selfish gene in light of the new findings of sociogenomics described by Conley is, therefore, a task for the future. I hope that evolutionary biologists will take up this challenge despite it being thrown up (inadvertently) by a sociologist!
1. G. E. Robinson, R. Bliss, M. E. Hudson, The genomic case against genetic determinism. PLOS Biology 22, e3002510 (2024).
2. G. E. Robinson, Integrative animal behaviour and sociogenomics. Trends Ecology & Evolution 14, 202–205 (1999).
3. G. C. Williams, Adaptation and natural selection: a critique of some current evolutionary thought, 1. Princeton paperback ed., 5. hardcover print (Princeton Univ. Pr, 1974).
4. R. Dawkins, The Selfish Gene (Oxford University Press, 1976).
5. J. A. Ågren, The Gene’s-Eye View of Evolution (Oxford University Press, 2021).
https://www.goodreads.com/book/show/213395522-the-social-genome
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