Did you know how tribal your mind is?

Categorizing human kinds is merely human -- by Carlin Romano
Review: Us and Them: Understanding Your Tribal Mind by David Berreby

By most accounts, the Paris riots grew because Interior Minister Nicolas Sarkozy ventured a generalization.

The rioters, Sarkozy told reporters, were "scum" and "hoodlums." Other group terms Sarkozy might have used, neutral and not-neutral, include "the disenfranchised," "fed-up Muslim youths" and "French citizens who are the children of former immigrants."

Perhaps the most important group term, left unspoken by the Interior Ministry, was "them" - the suggestion that rioters were a "them" assaulting an "us," the non-Muslim French establishment.

Would reading David Berreby's intellectually nervy new book have persuaded Sarkozy to be less harsh, if not less categorical? Hardly.

We are tribal thinkers about other people, or "human kinds," as Berreby puts it. The kinds may range from such hoary classes as "old people," to trendier sets like "NASCAR dads," to such ad hoc groupings as "the ladies on the 8:45 ferry."

Human kinds, Berreby writes, "serve so many different needs, there is no single recipe for making one." We organize kinds around the things people do, what they believe, where they come from or even how they occasionally look, as the Khmer Rouge did when slaughtering Cambodians who wore glasses.

Thinking in such kinds, argues Berreby, a longtime science writer, is "an absolute requirement for being human." It is "the mind's guide for understanding anyone we do not know personally, for seeing our place in the human world, and for judging our actions."

Us and Them arrives as an inspired mix of casual philosophy, applied science and acquired wisdom. Berreby wants us and them - whoever we are or they are - to understand how we organize our thinking about others, and draw lessons.

Broadly speaking, Berreby takes a pragmatist approach to generalization that would please John Dewey. Categories arise when minds with purposes meet a world full of obstacles. A laundry list like that of Emory psychologist Lawrence Barsalou - including "children, jewelry, portable TVs" - may look utterly arbitrary until its tie becomes clear: "Things to take out of a burning home."

Similarly, because the creation of human kinds remains tightly tethered to our purposes, they're hardly limp abstractions. "Aside from being messy conceptually," contends Berreby, "human kinds are sticky emotionally."

It doesn't matter that human kinds are socially constructed - most of reality is socially constructed. The issue of where we get the building materials is a separate one.

"Human kinds," Berreby wryly observes, "are real in just the way that money is real." It takes social consensus to treat small pieces of colored paper as valuable, but once the consensus is there, doubters are mere kooks.

Berreby's many provocative examples suggest the fluidity throughout history of our generalizations about people. In the 19th century, for instance, scholars such as the German Max Müller "took a Sanskrit word for noble and turned it into a term to describe a family of ancient languages." Müller insisted that the word referred only to languages, that "if I say Aryas, I mean neither blood nor bones, nor hair, nor skull."

Alas, Berreby reminds us, the term took on "tribal trappings" during Germany's march to Nazism. Before long, "Aryan was a life-and-death human kind."

Fluidity of human types also operates in science. In the 19th century, Berreby reports, some scientists divided people into the "phlegmatic" and "nervous." That crisp dichotomy no longer spurs lab research.

More recently, scientists viewed "Type-A personality" as an empirical category worthy of controlled experiment. But, as Berreby points out, while the phrase remains cultural jargon, scientists decided the idea didn't make testable sense. It's now on its way to "the heap of canceled kinds" that encompasses such social categories as cagots , a subgroup of the French that has faded away.

Berreby believes mind and brain science have "already begun to explain how and why people think and feel in tribes," why we're capable "of both tribal good and tribal evil." That science, he predicts, will "change ancient arguments" about tribal identities.

Much of Us and Them thus distills scientific findings. An example, already trickling down into nonscientific culture, is that one supposedly "natural" tribal identity - race - isn't.

"[H]uman genetics," reports Berreby, "doesn't support today's notion of race." Equally shaky is the idea of "ethnicity."

Does Us and Them provide any useful advice to Messieurs Chirac, Villepin and Sarkozy, as well as their angry street foes?

A first step to wisdom rests in Berreby's insight that any category is a "decision to treat individuals in a group as if they were all the same, which saves your time and attention for other things." Such rubrics make useful provisional tools for understanding others. The emphasis, however, should be on "provisional."

Individuals, we learn in life and love, take more work. Should French leaders and street protesters look into one another's eyes and start talking, many a category will fall away.