Are demographics destiny? Self-interest, sex, snakes, and the making of our political preferences.

• Author: Randazzo, Anthony
• Position: The Hidden Agenda of the Political Mind: How Self-Interest Shapes Our Opinions and Why We Won't Admit It - Book review

The Hidden Agenda of the Political Mind: How Self-Interest Shapes Our Opinions and Why We Won't Admit It, by Jason Weeden and Robert Kurzban, Princeton University Press, 387 pages, $29.93

Rich people hate taxes, right? Or at least that's what a rudimentary understanding of self-interest would suggest. But the story immediately gets more complicated when Warren Buffett and Bill Gates start arguing that their tax rates should be higher, even as the pro-business U.S. Chamber of Commerce cries out in opposition. And according to data from the U.S. General Social Survey, the owners of manufacturing plants and retail stores are more likely than lawyers and stockbrokers to oppose a tax increase. What's going on here?

One standard explanation is that the majority of lawyers and financial experts tend to be concentrated in major cities, among the more cultured, progressive elite, and thus tend to vote for Democrats. Meanwhile, most factory owners and retail-store CEOs are scattered across the conservative heartland and thus are more likely to vote Republican. There is some evidence for this, particularly in the donation patterns for the legal and finance industries compared to the manufacturing and retail industries.

Yet such an explanation is profoundly unsatisfying. It's amusing to believe we live in a country where there exists an "eastern elite" and a "left coast" with Jesusland in between. But the standard red state/ blue state tropes for why people develop specific political preferences are fraught with caveats, from "weird" liberal Austin, Texas, to the Republican mayors of New York City. Plus, while plenty of social science evidence suggests that political parties can shape their members' views, there still is the question of why a person self-selects into a political ideology in the first place.

The Pennsylvania Laboratory for Experimental Evolutionary Psychology psychologists Jason Weeden and Robert Kurzban believe they have the answer: a more robust understanding of what constitutes a person's self-interest.

In their new pop-political-psychology book, The Hidden Agenda of the Political Mind, the two researchers define self-interested behavior as "advancing any of a range of people's typical goals, whether directly involving material gain or something more subtle that advances someone's progress over the longer-term." To the degree that individuals identify with a particular group, whether it is based on gender, race, or socioeconomic...