This book is a wonderfully astute account of recent advances in the social sciences that is beautifully written and accessible to any literate adult. I despair, however, because as a social scientist I have to wonder why it takes a physicist to write such a book. The author might claim that only a physicist could have written this book. After all, the book advances a perspective Buchanan calls "social physics," a perspective that recognizes the free will of individual human atoms but still seeks to explain human social or collective patterns in the manner of physics, "where atomic-level chaos gives way to the clockwork precision of thermodynamics or planetary motion" (xi).
I am exaggerating when I speak of my despair, although I suspect that because many social scientists are needle-nosed specialists, most are incapable of Mr. Buchanan's synoptic vision. I do have a minor quibble with the author though and that is that at several points Mr. Buchanan takes his atomic/collective patterns metaphor a bit too seriously. It is after all just a metaphor. In fact, the brilliance of the book comes through not so much during its description of collective patterns--stock market fluctuations, rumors, neighborhood gentrification, crime waves, ethic violence-- but in the analysis of the features of atoms that make those patterns possible. The analogy with physics is interesting and arresting, but in physics one can literally be indifferent to the properties of individual atoms while explaining collective regularities, but, as Buchanan demonstrates very nicely, human social regularities arise directly from the (universal) properties or propensities of the human atoms. This is a roundabout way of saying that although the book as a whole is brilliant, the most important chapters are chapters 4, 5 and 6--"The Adaptive Atom," "The Imitating Atom," and "The Cooperative Atom." Each of these chapters describes a feature of human nature that is essential to our social lives and helps explain social patterns or regularities.
In the "Adaptive Atom," Buchanan draws mainly from the work of behavioral economists (especially Brian Arthur) that demonstrates the falsity of the "rational choice" model of human beings put forward by neo-classical economists. Rather than the omniscient, logical, calculating automatons neo-classical economists assume we are, the evidence is that we are adaptive agents--we take a step based upon a rule, idea, or belief and then adjust based upon the outcome (63). Our behavior is governed less by deduction than by trial and error. We recognize patterns, make predictions, and then adapt. Our decisions are typically made on the fly.
In the "Imitating Atom" Buchanan draws from a variety of social psychologists, sociologists and neuroscientists, to once again criticize an assumption of neo-classical economists, in this case the assumption that decisions are made by individuals in social vacuums. The evidence is that we are not isolated monads, but, rather, individuals who regularly seek information from others, especially in circumstances of insecurity, ambiguity and danger. Because of this propensity "social cascades" often result: behavior becomes more attractive the more people do it (103).
In the "Cooperative Atom" Buchanan draws chiefly from Peter Richerson, Robert Boyd, Joseph Henrich, Ernst Fehr and Herbert Gintis--all evolutionary thinkers with interests in anthropology and behavioral economics--to drive the final nail in the coffin of "rational choice" theory. The basic point of this chapter is that naturally human beings are not purely self-interested but, rather, "strong reciprocators." We are capable of genuine kindness to those beyond family and friends and we also display righteous indignation toward free riders and those who violate the canons of justice. According to Buchanan and the authors from whom he draws, these features of our nature emerged not through individual competition within groups--such competition favors selfish traits--but via competition between different (cultural) groups. Two decades ago this position was considered heretical among evolutionary thinkers but the evidence has made it a perfectly plausible position among evolutionary social scientists in the last few years and I suspect it will be the consensus view within a few more years among those willing to consult the data.
This brief summary makes it sound as though the book is chiefly an argument against "rational choice" theory, which it is not. Given the importance of "rational choice" theory in economics and, to a lesser degree within sociology, demonstrating the profound failings of the theory is important, but Buchanan also gives "postmodernism" attention, dismissing it as silly claptrap. Additionally, he discusses the tiresome efforts of many social scientists "who have raised the flag of permanent defeat and busy themselves with rehashing the works of great thinkers of the past" (18) and yet other social scientists who mistake the identification of "correlations" for genuine explanations. The most important contribution this book makes, however, is not negative but positive. It is the truly fine summaries of the ideas of thinkers such as Richerson, Boyd, Hernrich, Fehr and Gintis who, along with similarly inclined social scientists, are working to advance and unify the social sciences on a sound empirical basis guided by an evolutionary theory of culture. I recommend this book to anyone interested in the most important recent work being done in the social sciences but I would also recommend that after reading the "Social Atom" one move on to the original sources as well. Richerson and Boyd's Not by Genes Alone: How Culture Transformed Human Evolution or Henrich et al's Foundations of Human Sociality would be especially good places to start.
Brad Lowell Stone
