Excerpt from Us and Them by David Berreby, plus links to reviews, author biography & more

Math may be the most rational of activities, but it's apparently not free of the sort of human-kind thinking that tells you women aren't so good at it, while Asians are. This does not mean that all human kinds make you change; it does mean that they have that potential, and being a human being, you know it.

Professionally, as I've mentioned, many scientists want nothing to do with such an emotional and conceptual swamp. Human-kind categories are fine for life outside the lab - sure, set up a committee to attract more minorities into our field; yes, let us try to make our nation a leader in stem-cell research. But nations, minorities, creeds, professions, as an object of scientific research? Leave that to colleagues with a screw loose or, worse, to cranks and journalists. This is not to say that scientists are less tribal than anyone else. The passions of Us and Them affect them too. In fact, feelings about nation, religion, culture, tradition, and other human kinds have helped to motivate scientific work, as they have helped to motivate almost all organized activities, for good and for ill, from Olympic athletics to mass murder.

For example, modern neuroscience rests on the successes of the great Spanish anatomist Santiago Ramón y Cajal, who finished publishing his masterpiece on the brain and nervous system in 1904. In another example of the ever-changing character of scientific knowledge, Cajal's work ended a long debate about whether the human brain consisted of distinct cells at all. He championed the neuron doctrine - that the brain, like every other organ, was made up of millions of distinct cells, the neurons. (Nowadays the brain is described as neurons and glial cells, but the central argument, which Cajal won, was that it was not organized differently from the rest of the body.)

When the book was published, Spain had just lost a war to the United States, and that unscientific fact was much on the author's mind.

"Above all," Cajal wrote in his autobiography, "I wanted my book to be - please excuse the presumption - a trophy to be laid at the feet of our prostrate national science and an offering of fervent devotion by a Spaniard to his scorned country." Clearly, Cajal valued his fervent devotion. Yet he did not study patriotic neurons or Spanish neurons, but all neurons. He saw brain cells as a scientist, but apparently he saw his book about cells as a patriot.

Well, as the cognitive scientist George Lakoff of the University of California at Berkeley has put it, ask different questions, you get different answers. The rules of patriotism and the rules of the lab aren't the same. The best way to live with different systems of rules is not to try to fit them together, because they don't align. It's quite enough work to keep clear about how each system is different from the others.

On the one hand, philosophy and psychology, at least in the West, have largely focused on the individual soul. In these fields there was never as great an interest in how people came to believe in mass entities, like nations, religious communities, and social classes. For instance, Sigmund Freud's interpretation of "group psychology" stresses the fears and frustrations of the unconscious mind, which, he held, is formed in early childhood. By this light, today's experience is far less important than the earliest days of one's life. Armies, churches (Freud's examples) as well as race, religion, nationality, and all the other "groups" are turned into fodder for the psychoanalytic apparatus that explores your dreams and your attitude toward masturbation.

Copyright © 2005 by David Berreby.  No part of this book maybe reproduced without written permission from the publisher.