In Our Political Nature, Avi Tuschman comes down rather firmly on the side of nature in the nature-nurture debate. He states that “our political orientations are actually natural dispositions, molded within each of us by powerful evolutionary forces” (p. 11). One would certainly not dispute that natural dispositions play a role in shaping political attitudes. However, Tuschman’s declaration that their primacy is more debatable, and far from clear. Tuschman’s argument is that political orientations arise from three clusters of personality traits: differing attitudes toward tribalism; differing assumptions about inequality; and differing perceptions of human nature. Conservatives tend to be more ethnocentric and hierarchical than liberals, and they believe people are more competitive than cooperative. Liberals tend to be more xenophilic and egalitarian, and they believe people are more cooperative than competitive.

Tuschman explains the basis of these differences in political ideology by what he terms the “Evolutionary-Origins Argument.” This argument examines the evolutionary roots of the three aforementioned clusters. The biology of tribalism, which looks at inbreeding and outbreeding, explains the dichotomy between ethnocentrism and xenophilia. The biology of family conflict, which looks at why families do not always get along despite being so biologically similar, explains the dichotomy between hierarchy and egalitarianism. Finally, the biology of altruism and self-interest, which looks at how and why people cooperate, explains the dichotomy between cooperation and competitiveness. In making these comparisons, Tuschman hopes to show that the formation of our political ideologies goes beyond what is shaped by our experiences; things are more complicated than is commonly believed. By so arguing, he hopes to “raise the level of our political discourse and strengthen our noble democratic processes” (p. 13). If we better understand why we are different, then perhaps that understanding will lead to greater civility in politics.

Although Tuschman claims that genetics is the dominant factor in our political orientation, a much more complex and ambiguous picture emerges from the evidence he presents. For example, one of the key pieces of evidence he cites to support this claim is a 2005 article by Alford, Funk, and Hibbing,^{Reference Alford, Funk and Hibbing1} which concludes (on the basis of twin studies) that “40 to 60 percent of the variation in our political attitudes comes from genetic differences between individuals. The remaining differences come from environmental factors” (pp. 26–27). Forty to sixty percent is a wide range. One could claim on the basis of such evidence that genetics plays a significant role in our political attitudes but that role is not necessarily a decisive one, even though Tuschman seems to claim that it is.

What is most impressive in this book is the breadth of the research that Tuschman has catalogued. Among the more interesting studies are those asking whether courtship results in greater political polarization than does arranged marriage. A 2011 study by Alford and colleagues looked at marriages begun in the 1980s and found that the strongest similarity among spouses was their party affiliation and political ideology.^{Reference Alford, Hatemi, Hibbing, Martin and Eaves2} A 2013 study by Klofstad, McDermott, and Hatemi projected increased polarization by estimating marriage trends based on dating website profiles. According to their model, after 20 generations, the proportion of political extremists would increase from 4.5 percent to 11.2 percent while the proportion of political moderates would fall by 17 percent. The authors speculated that a factor in this trend has been progress toward gender equality from the turn of the twentieth century. When both mates have a high degree of freedom in their choice of a spouse, a higher degree of positive assortative mating would be expected. As a result, existing political ideals would be reinforced.^{Reference Klofstad, McDermott and Hatemi3}

Although it does not break new ground itself, and even if its author does overextend his conclusions, this book seems well suited to introduce readers to the role that evolutionary factors might play in shaping political attitudes. It faithfully presents relevant research and is written in a clear, easy-to-read style. It is also a timely book, especially for nonexpert readers who have seen articles in the popular press about how genetics influence political behavior⁴ and want to know more. However, readers will not get a well-rounded view of the debate from this book as Tuschman does not spend much time presenting the case for alternative perspectives.

Tuschman does seem to moderate his “pro-nature” position in the book’s conclusion, recognizing that environmental factors play a “substantial” role in the development of our political attitudes. However, for a more balanced presentation of the debate, readers may wish to seek out Matt Ridley’s book Nature via Nurture (2003).^{Reference Ridley5} For example, in his last chapter, Ridley examines the (italicized) gene, MAO-A, coding for the (not italicized) enzyme monoamine oxidase A, MAO-A. He notes that people with a version of MAO-A associated with low MAO-A activity are more likely to exhibit antisocial behavior; however, he also documents that maltreatment in youth is a typical correlate of—and, less certainly, the (or a) trigger for—the antisocial behavior with which the low-activity gene variant has been associated.

Tuschman’s book is a useful resource for anyone interested in this subject. In academia, it could be used in classes of advanced undergraduates or as an introduction to the study of politics and the life sciences for graduate students.