In his provocative new book, political anthropologist Avi Tuschman offers science to show that how you vote reflects your genes as much as your personal history, economic self-interest, and current issues. (More)

Our Political Nature Part I: Openness and Tribalism

This week Morning Feature explores Avi Tuschman’s new book Our Political Nature: The Evolutionary Origins of What Divides Us. Today we see how ‘social issues’ like racism and gender roles reflect evolutionary impulses for inbreeding and outbreeding. Tomorrow we’ll see the familial evolutionary roots of our different views on wealth inequality. Friday we’ll examine why conservatives see life through the lens of competition, while liberals see it through the lens of cooperation. Saturday we’ll discuss how to apply these insights in talking with Fred, our archetypal median voter.

Avi Tuschman earned a Ph.D in evolutionary anthropology from Stanford University. He has worked with presidents, prime ministers, diplomats, and legislators on five continents, as well as with multilateral banks to mediate social and economic conflicts in developing countries.

Please welcome Dr. Tuschman as he joins our discussions this week.

Half an OCEAN apart

We commonly imagine that we learn about politics in school and at home, adopting or rejecting our parents’ political values as we gain life experience, and apply those values and experience to the issues in order to make rational voting decisions. Yet a surprising study by Jack and Jeanne Block found that’s less true than we imagine.

The Blocks selected 128 three-year-olds and asked preschool teachers to watch them closely for seven months. The teachers then scored the children’s personalities and social interactions on a common, standardized test. The Blocks repeated the study a year later, with the same children but different teachers … and then locked the results in a vault.

Twenty years later, the Blocks found 95 of their original subjects and asked the 24-year-olds for their opinions on a range of highly partisan, hot-button political issues. The results were astonishing. The Blocks found a clear pattern of childhood personality traits that accurately predicted adult political leanings. The vast majority of the children who were “uncomfortable with uncertainty” and “relatively over-controlled” (among other similar traits) grew up to be conservatives … and the vast majority of the children who were “autonomous, expressive, energetic, and relatively under-controlled” (again, among other similar traits) became liberals.

The Blocks’ testing fit measures of the Big Five personality traits – Openness to Experience, Conscientiousness, Extroversion, Agreeableness, and Neuroticism – commonly referred to by the acronym OCEAN. Their findings have since been compared to studies of twins separated at birth, and data from other psychological studies around the world, and the results show a consistent pattern:

  • Although medians and variances vary, scores for the Big Five traits form a normal distribution curve within cultures around the world.
  • In cultures around the world, people who score higher on Openness and lower on Conscientiousness are much more likely to be liberal, while people who score lower on Openness and higher on Conscientiousness are much more likely to be conservative, within their own cultures.
  • A higher score on Extraversion also predicts liberalism, but less strongly than higher Openness and/or lower Conscientiousness.
  • In cultures around the world, these personality traits were more stable and statistically reliable predictors of political behavior than demographics such as age, gender, or income.

Dr. Tuschman argues that we are politically divided by our personality traits of Openness, Conscientiousness and, to a lesser extent, Extraversion – half an OCEAN – and that the genetic variance of dispositions toward each of those traits is rooted conflicts that have shaped and still shape our evolution as a species.

Determinism and the Moralistic and Naturalistic Fallacies

I’ll pause here to emphasize that Dr. Tuschman does not argue genetic determinism. Our genes seem to predispose us to be more or less Open, Conscientious, and/or Extroverted – thus more conservative or more liberal – but those correlations are in the range of 40-60%. That is, our genes seem to be about half the story, and the other half is indeed culture and life experience. He also explicitly rejects two common logical fallacies:

In other words, Dr. Tuschman does not limit his evidence to science that fits his own moral and political outlook, nor does he argue that the evolutionary basis of liberal or conservative traits ‘proves’ their moral correctness. It simply proves that, when it comes to politics, we act – at least in part – on biological impulses that seem to be universal both around the world and throughout human history.

Inbreeding and Outbreeding

Liberals tend to score higher than average on Openness, and are generally more willing to see new places, try new foods and new ideas, and welcome and seek out different kinds of people. Oh … and mate with them.

On the other hand, conservatives score lower on Openness, and generally prefer to stay closer to home, preserve family traditions, exclude outsiders, and socialize within kinship communities. Oh … and mate with them.

That “and mate with them” is very important. In fact, Dr. Tuschman argues that the risks and benefits of outbreeding and inbreeding explain the natural variation in genes that predispose us to Openness, and also explain “social issues” that divide liberals and conservatives.

From a purely evolutionary perspective – that is, how many of your grandchildren live to adulthood – the ideal human mate seems to be a third- or fourth-cousin. Dr. Tuschman presents evidence that this level of kin-bond offers enough close genes to preserve beneficial family traits, and enough distant genes to mask negative family traits and introduce beneficial outsider traits.

In cultures around the world, conservatives tend to be more tribal: living in communities linked by stronger-than-average (for their cultures) kinship bonds. They are also more likely marry first- or second-cousins. Inbreeding has genetic risks, such as more often activating recessive genes that trigger birth defects. But it also has benefits, such as more often activating and combining genes that boost immunity to local pathogens or otherwise fit the local environment. Inbreeding – and shunning outsiders – also helps to keep away new diseases. Conservatives tend to have more children than average (for their cultures), but fewer of their children reach adulthood and they have fewer grandchildren than average. Conservatives also tend to favor strict gender roles and other norms that encourage inbreeding and reserve sex for reproduction

Conversely, liberals tend to be more cosmopolitan, living in cities with weaker-than-average (for their cultures) kinship bonds. They are more likely to marry outside outside their race, ethnicity, or religion. Outbreeding – and welcoming outsiders – also has genetic risks and benefits, primarily the converse of those described above. Liberals tend to have fewer children than average (for their cultures). More of their children reach adulthood, but they have fewer grandchildren than average (for their cultures). And liberals tend to favor more gender roles and other norms that encourage outbreeding and sex without reproduction.

“Centripetal pulls” and “centrifugal pushes”

In other words, evolution favors genetic diversity, up to a point. And, Dr. Tuschman argues, this is why evolution yields a natural variance in the genes that predispose us to Openness. Conservatives within a culture provide what he calls “centripetal pulls” that keep tribes together, while the liberals provide “centrifugal pushes” that encourage exploration and bring in new genetic stock.

Dr. Tuschman argues that plays out in social issues such as racism, religious pluralism, gender equality, and reproductive rights. On these and other “social issues,” in cultures around the world, people who score lower on Openness tend to favor “conservative” policies that emphasize and benefit tribal reproduction, while people who score higher on Openness tend to favor “liberal” policies that emphasize and benefit cosmopolitan reproduction.

Tomorrow we’ll see how the trait of Conscientiousness strongly predicts liberal or conservative positions on economic issues, especially income inequality, and how a natural variation of that trait also has evolutionary roots.


Happy Wednesday!