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Professor Oded Galor of Brown University and his co-workers have produced a complex and sophisticated defense of a genetic factor or dimension in comparative economic development.

Human Genetic Diversity and Comparative Economic Development

Ashraf, Quamrul
Galor, Oded
This research contributes to the understanding of human genetic diversity within a society as a significant determinant of its economic development.

The hypothesis advanced and empirically examined in this paper suggests that there are socioeconomic trade-offs associated with genetic diversity within a given society. The investigation exploits an exogenous source of cross-country variation in genetic diversity by appealing to the “out of Africa” hypothesis of human origins to empirically establish a highly statistically significant and robust non-monotonic effect of genetic diversity on development outcomes in the pre-colonial era.

Contrary to theories that reject a possible role for human genetics in influencing economic development, this study demonstrates the economic significance of diversity in genetic traits, while abstaining entirely from conceptual frameworks that posit a hierarchy of such traits in terms of their conduciveness to the process of economic development.

Human Evolution and Economic Development

Ashraf Quamrul and Oded Galor, “Human Genetic Diversity and Comparative Economic Development,” January 24, 2008

Galor Oded and Omer Moav, “The Neolithic Origins of Contemporary Variation in Life Expectancy”, November 2007

¨ Review in Gene Expression

Galor Oded and Stelios Michalopolous, “The Evolution of Entrepreneurial Spirit and the Process of Development”, April 2006

Galor Oded and Omer Moav, “Natural Selection and the Origin of Economic Growth,” Quarterly Journal of Economics, 117, 1133-1192 (November 2002)

¨ Emerging Research Fronts, Web of Science, 2006

¨ Review in Gene Expression, 2007

¨ Review in Science Daily, 2002

¨ Discussion by Joel Mokyr, AEA 2002

¨ Presentation, 2002 (Video)

¨ Presentation, 2002 (Slides)


This research develops an evolutionary growth theory about the interplay between the evolution of mankind and economic growth since the emergence of the Homo sapiens. For the major part of human existence mankind was engaged in a persistent struggle for existence. Diminishing returns to labor, along with a positive effect of the standard of living on population growth, held income per capita near subsistence level. Improvements to the technological environment or in the availability of land led to larger but not wealthier populations.

This pressure to adapt to changing environments, conceivably affected the composition of the population as well. Over time, the lineages of individuals whose characteristics were complementary to the changing technological environment gained an evolutionary advantage. They generated higher income, devoted more resources to child rearing, and their fraction within the population gradually rose.

The Agricultural Revolution and the establishment of individual, rather than tribal, property rights expedited the selection process and gradually increased the representation of traits that were complementary to the growth process (e.g., entrepreneurial spirit, higher life expectancy, preference for child quality). It triggered a positive feedback between technological progress and education and ultimately bringing about the Industrial Revolution and a period of sustained economic growth.

Moreover, contrary to theories that reject a possible role for human genetics in influencing economic development, some of this research demonstrates the importance of genetic factors by highlighting the effects of diversity in genetic traits, while abstaining entirely from conceptual frameworks that posit a hierarchy of such traits in terms of their conduciveness to the process of economic development.

The “Out of Africa” Hypothesis, Human Genetic Diversity, and Comparative Economic


This research argues that deep-rooted factors, determined tens of thousands of years ago, had a significant effect on the course of economic development from the dawn of human civilization to the contemporary era. It advances and empirically establishes the hypothesis that in the course of the exodus of Homo sapiens out of Africa, variation in migratory distance from the cradle of humankind to various settlements across the globe affected genetic diversity and has had a direct long-lasting effect on the pattern of comparative economic development that could not be captured by contemporary geographical, institutional, and cultural factors.

In particular, the level of genetic diversity within a society is found to have a hump-shaped effect on development outcomes in the pre-colonial era, reflecting the trade-off between the beneficial and the detrimental effects of diversity on productivity. Moreover, the level of genetic diversity in each country today (i.e., genetic diversity and genetic distance among and between its ancestral populations) has a similar non-monotonic effect on the contemporary levels of income per capita.

While the intermediate level of genetic diversity prevalent among the Asian and European populations has been conducive for development, the high degree of diversity among African populations and the low degree of diversity among Native American populations have been a detrimental force in the development of these regions.

Further, the optimal level of diversity has increased in the process of industrialization, as the beneficial forces associated with greater diversity have intensified in an environment characterized by more rapid technological progress.

Editorial Reviews


“There have been a number of more or less complex variants on this . . . metaphor for genetic evolution and it is generally agreed that the most nuanced and sophisticated version is contained in the work of Robert Boyd and Peter Richerson, and laid out in considerable detail in Not By Genes Alone.”—Richard Lewontin, The New York Review of Books

(Richard Lewontin The New York Review of Books 20060101)

“Drawing on new ideas about multilevel selection, evolutionary psychology and . . . ‘strong reciprocity’ (the bestowing of rewards and punishments even where there is no direct personal gain for this behavior), Richerson and Boyd build a case for a special role for cultural processes in human evolution. . . . It is a book full of good sense and the kinds of intellectual rigour and clarity that we have come to expect from [the authors].”—Robin Dunbar, Nature

(Robin Dunbar Nature )

“Ambitious and wide-ranging. . . . The writing is lucid, even eloquent. . . . Richerson and Boyd have done a rare thing: Casting their net widely across a range of disciplines, in order to tackle the most complex phenomenon of our species, and they have achieved consilience. Read and ponder.”—W. C. McGrew, Journal of Human Evolution

(W. C. McGrew Journal of Human Evolution )

“Writing in a much more accessible form than they have before, Richerson and Boyd lay out their case for the role of culture in shaping the human mind and behavior. . . . . This book provides an excellent account of Richerson and Boyd”s theory, and is a must-read for anyone interested in gene-culture coevolution.”—Susan Blackmore, Bioscience

(Susan Blackmore Bioscience )

“[The] subject, the place of culture in human evolutionary dynamics, is relatively neglected, and is rarely as well debated as it is here. . . . Indeed, their text deserves to be considered by all of us in any field of archaeology.”—Don Brothwell, Antiquity

(Don Brothwell Antiquity )

“This is an important work that is sure to generate lively discussion on a topic crucial to our understanding of ourselves.”

(Northeastern Naturalist )

“Richerson and Boyd have produced an excellent explication and overview of the current state of the research on cultural evolution . . . and the relative roles of genes and culture in human evolution and behavior from the Pleistocene to the present–and they have done all this in a rigorous but non-technical, easily readable format. I think that both those who are just beginning to explore the evolutionary sources of human behavior and those who are currently engaged in work in this area will greatly benefit from reading this book.”

(Adam Gifford, Jr. Journal of Bioeconomics )

Product Description

Humans are a striking anomaly in the natural world. While we are similar to other mammals in many ways, our behavior sets us apart. Our unparalleled ability to adapt has allowed us to occupy virtually every habitat on earth using an incredible variety of tools and subsistence techniques. Our societies are larger, more complex, and more cooperative than any other mammal’s. In this stunning exploration of human adaptation, Peter J. Richerson and Robert Boyd argue that only a Darwinian theory of cultural evolution can explain these unique characteristics.

Not by Genes Alone offers a radical interpretation of human evolution, arguing that our ecological dominance and our singular social systems stem from a psychology uniquely adapted to create complex culture. Richerson and Boyd illustrate here that culture is neither superorganic nor the handmaiden of the genes. Rather, it is essential to human adaptation, as much a part of human biology as bipedal locomotion.

Drawing on work in the fields of anthropology, political science, sociology, and economics—and building their case with such fascinating examples as kayaks, corporations, clever knots, and yams that require twelve men to carry them—Richerson and Boyd convincingly demonstrate that culture and biology are inextricably linked, and they show us how to think about their interaction in a way that yields a richer understanding of human nature.

In abandoning the nature-versus-nurture debate as fundamentally misconceived, Not by Genes Alone is a truly original and groundbreaking theory of the role of culture in evolution and a book to be reckoned with for generations to come.

“I continue to be surprised by the number of educated people (many of them biologists) who think that offering explanations for human behavior in terms of culture somehow disproves the suggestion that human behavior can be explained in Darwinian evolutionary terms. Fortunately, we now have a book to which they may be directed for enlightenment . . . . It is a book full of good sense and the kinds of intellectual rigor and clarity of writing that we have come to expect from the Boyd/Richerson stable.”—Robin Dunbar, Nature

Not by Genes Alone is a valuable and very readable synthesis of a still embryonic but very important subject straddling the sciences and humanities.”—E. O. Wilson, Harvard University

Product Details:

· Hardcover: 342 pages

· Publisher: University Of Chicago Press; 1 edition

· December 31, 2004

· Language: English

· ISBN-10: 0226712842

· ISBN-13: 978-0226712840

Not By Genes Alone by Peter J. Richerson and Robert Boyd explains something that should seem simple. Genes made us, we made culture, so genes shaped culture. Yet culture also helped shape us, so genes and culture interact together and work together to make us. But HOW do you do research on culture and link it to genes? Well, if culture also acts like genes, then what you want to do it treat it like genes.

And that is what the book does. It studies culture from an evolutionary point of view, breaking it down to traditions and values, making these the genes of culture. Culture evolves, adapts and sometimes even causes problems, bringing about the extinction of the culture. One culture might work better than another and overwhelm the weaker, less fit culture.

By using the ideas and knowledge that Darwin has passed down to us the authors were able to understand how genes and culture worked together to shape us. Lots and lots of detailed, data rich, chapters.

Some years ago, Richard Dawkins published “The Selfish Gene”, explaining how gene survival was fundamental in natural selection. He also coined the term “meme” to explain the dissemination of ideas across societies. Almost immediately, there was a strident chorus of objection, based on the theme of “you can’t say that about humans!” The outcry hasn’t ceased, but in the case of Richerson and Boyd, it’s become somewhat muted.

This book is designed to gently persuade you that human evolution rests on a solid “cultural” base. Biology is under there somewhere, but for humanity, cultural impact overwhelms our genetic roots.

The authors would like to abandon the dichotomy of what’s usually referred to as the “nature versus nurture” debate. That’s admirable, but not only has that contest been challenged elsewhere, finding anyone adhering to either position as an absolute is difficult, if not impossible. Who claims “genes” are the sole behaviour drive? Not even religions, the most dogmatic element in our society, any longer label infants as “blank slates” to be moulded at will. Individuality and expression may be curtailed, but not constrained. Yet that curtailment, even if only mindless imitation, is the foundation of this book. Instead of the chaos of individual response to environmental pressures, “culture” guides behaviour to the extent that groups become predictable in their activities. For them, “culture” is a sort of behavioral umbrella keeping families and small communities from unraveling the fabric of society.

Richerson and Boyd gather a wide spectrum of studies to erect their cultural edifice. They examine studies of social animals, scrutinize the grim world of economics and wonder how it is that of all species, human beings filled nearly every environmental niche. They accept the complexity of human society as naturally hierarchical. That organization, coupled with a strong imitative/cooperative sense enabled our species to readily adapt to so many ecological niches. Where some say, “If it works, don’t fix it!”, Richerson and Boyd counter, “If it works, imitate it!” Human beings, they contend, are better imitators than other species because we can judge long-term impacts of actions. This talent, coupled with language, provides our unique adaptability in varied environments. We can test for success and pass our findings to our neighbours. This gives groups within our species both unique abilities and the means to improve them. Not all of humanity is but one culture. It’s a melange of groups, each culture representing a regional or social norm.

“Group selection” is the offshoot of an older, flawed, evolutionary concept – “species selection”. With the idea of “species selection” quickly demonstrated as false, group selection arose to replace it. A close look at group selection reveals that it’s but another mechanism to keep humanity separated from the remainder of the animal kingdom. If you downplay any similarities between us and other beasts, you are able to retain a “divine spark” or other metaphysical notions for humanity. And only humanity. Richerson and Boyd’s use of animal behaviour studies to ameliorate this distinction are a welcome addition to social studies. However, these examples are carefully selected and interpreted by the authors. They aren’t set in an evolutionary context, but are given solely as a contrast to the also carefully chosen aspects of human behaviour. The book raises a number of interesting questions.

In the concluding pages of this book, Richerson and Boyd observe that universities have introductory courses in psychology, sociology, economics and political science in which students “are encouraged to think that the study of humans can be divided into isolated chunks corresponding to these historical fields.” There is, however, no Homo Sapiens 1 or 101, “a complete introduction to the whole problem of understanding human behavior.” The authors note that the chief reason no such course exists is “that the key integrative fields have not yet developed in the social sciences” and that “a proper evolutionary theory of culture should make a major contribution to the unification of the social sciences. Not only does it allow a smooth integration of the human sciences with the rest of biology, it also provides a framework for linking the human sciences to one another.” Evolutionary theory can and should integrate the social sciences with each other and biology and that this book could and should serve as the foundational text for Homo Sapiens 101.

There are dozens of books available employing evolutionary thinking to humans, the large majority of which do not offer a “proper evolutionary theory” because they neglect the most obvious and unique feature of our species–our culture, information affecting behavior acquired from other humans through social transmission. This failure results from a steadfast dedication to accounting for human behavior in terms of principles applicable to the prosocial behavior of other species– kin selection and reciprocity. In an attempt to not stray from “orthodox” neo-Darwinism, neo-Darwinians have failed to fully acknowledge, let alone explain, the most salient feature of our species–a fact that “social contructivists” use to dismiss evolutionary theory. Richerson and Boyd recognize the “ancient social instincts” of kin altruism and reciprocity but they also acknowledge and give appropriate attention to what they call the “tribal social instincts.” These instincts, which probably emerged during the dramatic climate variations of the late Pleistocene, allow members of our species to identify with, dedicate themselves to, and take normative direction from, groups of people that include hundreds to thousands of people beyond kin and friends. These tribal instincts are accommodated in complex societies such as our own through “work-arounds,” institutions such as religious organizations, political parties, voluntary associations and other symbolically marked groups that exploit our inclination toward particularistic community attachment. Originally, though, these instincts co-evolved in a ratcheting process with our language, capacity for perspective taking, morality, religion and “culture” broadly conceived. We are a thoroughly unique groupish species and the only species on which group selection of cultural variants has played a role.

As Richerson and Boyd argue, genes and culture have co-evolved within our species. Culture has been primary in the environment selecting features of our genotype. Those humans incapable of cooperating in tribal settings were ostracized and were unlikely to find mates. They were less likely than cooperators to survive and reproduce. Culture has molded our genetic make-up just as our genes have directed the development of our culture.

This book provides Darwinians and social constructivists in the social sciences and the humanities grounds for common discussion and possible agreement.

Human Genetic Diversity and Comparative Economic Development

Not By Genes Alone by Peter J. Richerson and Robert Boyd


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