Extended evolutionary synthesis needs to include the social sciences

It is an intellectual riddle—why is it that the biological and social sciences are divided into so many separate fields? If there was a “new synthesis” for evolutionary biology almost a hundred years ago, how did it manage to exclude (or get excluded by) the burgeoning fields of research that study the social behaviors of humans?


Consider this partial list on the social science side: anthropology, cultural geography, economics, history, political science, psychology, and sociology. What do these fields have to do with each other? Do metaphysically or methodologically real boundaries exist between them? Why has no unified School of Social Sciences ever come into existence within the academy?


One could even go more granular and look at programs in early childhood education, media studies, or business management… in each case, like a fractal, the same patterns of fragmentation and division are reproduced. Now that there is an earnest research program to test hypotheses about epigenetics, morphological biases in development, and the feedbacks of social learning in an “extended” evolutionary synthesis (EES), I would like to make the call that we don’t merely go halfway by extending the field of biology without also bringing greater coherence to the social sciences as well. Let us get right to the core of the historic divisions that plague the study of social behavior and weave an evolutionary tapestry capable of integrating all of the social sciences with their sister fields of biology, ecology, and planetary science.


But first, the practical motivation. Why do this now?


The answer is glaring in both its urgency and its absence as a driver of intellectual discourse. Humanity is altering the biodiversity of our home planet. Among the consequences of our cultural evolution is the destabilization of Earth’s climate and a geologic shift away from the Holocene into a new era that has been dubbed the Anthropocene. In a word, we are destroying the very ecosystems on which we depend for our collective survival. Piecemeal solutions and fragmentary insights simply won’t cut it. This is a time for all-hands-on-deck and it will require a process of knowledge synthesis unprecedented in the history of universities or the civilizations from which they sprang.


With this context in mind, I will trace a very brief outline of the historic chasm between biology and the social sciences that the EES program can help ameliorate. My sketch begins with a quote from one of the pioneering figures for the field of psychology:


“Organic matter, especially nervous tissue, seems endowed with a very extraordinary degree of plasticity of this sort; so that we may without hesitation lay down as our first proposition the following, that the phenomena of habit in living beings are due to the plasticity of the organic materials of which their bodies are composed.”


The Principles of Psychology by William James (1890)


Here we have the beginnings of a science for human behavior, written almost one hundred and thirty years ago, that seeks to explain the plasticity of behavior for complex animals that have a central nervous system. This approach—building on findings from biology to explain social behavior—appears again and again in the successful efforts of later investigators. We see it in the pragmatic “selection by consequences” of B.F. Skinner’s behaviorism (1940s and 50s) and in the methodological designs of public policy research by the social theorist, Donald Campbell (1970s). It is mirrored in the nonhuman world by ethologists studying animal behavior in the likes of Niko Tinbergen (1950s) and developmental biologists who study entire life cycles such as John Tyler Bonner (1970s).


What I observe while reading the scholarly works of these traditions is a continuous referencing back to evolutionary arguments. Each in their own way is striving to understand how animals function in their environments around the complex interplay of modifiable behaviors with diverse strategies for achieving reproductive success. All of this is most powerfully seen in the explosive growth of agent-base modeling approaches across every social science (summarized nicely in the 1998 edited volume Game Theory & Animal Behavior).


It is interesting to discover that while the evolutionary synthesis in biology gave rise to a period of genetic reductionism, where the powerful mathematical tools of population genetics were employed to capture the genetic consequences of social behaviors as reproductive outcomes in a population, there was in parallel with it a growing synthesis of biology and social science in the bodies of work cited above. Most dramatic among these efforts was the 1975 book Sociobiology: The New Synthesis by E.O. Wilson that received widespread acclaim for all but the last chapter which was dedicated to the study of humans.


Said another way, no chasm actually exists as far as social behavior research is concerned! What we see in the silos of university departments is more an artifact of “morphological structures” in their administration than a fundamental challenge at the conceptual foundations of scholarly work in the field.


Back to my original question then, why isn’t there a unified approach to social sciences?


A nice overview can be found in Steven K. Sanderson’s 1990 book Social Evolutionism: A Critical History where he outlines the major critiques brought against evolutionary approaches by social theorists. Among them are concerns about “developmentalist” logic and the “stage theories” where civilizations are treated as the dynamic attractors toward which all social evolution ultimately flows. The hubris of false notions of progress gets stood up as a kind of straw man around what Sanderson shows to be a variety of simplistic misunderstandings about how evolution works. It is no surprise that many social theorists take issue with such caricatures.


Said another way, it is those social theorists who take the time to dig into the nuances of evolutionary mechanisms and processes who grow a deep appreciation for how the diffusion, development, and accumulation of social change can be studied using frameworks from biology. They discover powerful analytic tools and empirical knowledge to help them make sense of the immense real-world complexities that they grapple with in their own fields. But those who merely dip in the shallow waters of evolutionary thought are likely to come away dissatisfied by what they see as too mechanistic, rigid, linear, and reductionist.


A “quiet revolution” of sorts has been slowly growing for bridge-building between biology and the social scientists. One domain that has proven especially fruitful was the translation of population genetic tools to the study of cultural change. Pete Richerson and Rob Boyd built upon the mathematical frameworks developed by Luca Cavalli-Sforza and Marcus Feldman to formalize the study of cultural transmission—an effort initiated in the late 1970’s and brought to completion a decade later. We can see that the evolutionary synthesis was broadening this whole time to make a Grand Synthesis of Biology and Culture possible in the early 21st Century. Indeed, this is the mission of the newly founded Cultural Evolution Society I was tasked with a Templeton Foundation grant to help create.


So as we go about the detailed work of testing epigenetic and developmental models for biology that show how important environmental factors are as inheritance systems in their own right, let us also recognize that the tools are shovel-ready for extending this synthesis to include the full complexities of social systems at community, societal, and even planetary scales.


If we fail to incorporate the conciliatory patterns of evolution and complexity that span all existing social sciences, we will find ourselves in the unfortunate position of watching the Earth’s biosphere unravel knowing that all the pieces were in place to take the whole-systems approaches to guiding cultural evolution that might have saved us. Luckily, as I hope I’ve shown here, the historic roots of such a synthesis are already deep and fixed in the foundations of many social scientific fields already.





Joe Brewer is the Executive Director of the newly forming Center for Applied Cultural Evolution. He is also a pioneer and advocate for the field of culture design—applying insights from the cognitive, evolutionary, and social sciences to help facilitate large-scale social change in communities around the world.