Gary Marcus thinks your brain is a kluge. (Mine, too: We all have a prefrontal cortex piled on top of a primitive hindbrain. The thinking process that emerges isn't always pretty.)
"When I can do something stupid even as I know at the time that it's stupid," Marcus writes, "it seems clear that my brain is a patchwork of multiple systems working in conflict. Evolution built the ancestral reflexive system first and evolved systems for rational deliberation second." We're all 98 percent chimpanzee, he says, so "the vast majority of our genetic material evolved in the context of creatures who didn't have language, didn't have culture, and didn't reason deliberately."
In his chapter on memory -- there are also sections on how we think (not clearly), make decisions (not wisely), communicate (ambiguously) and pursue happiness (in truly odd ways) -- Marcus illustrates his book's subtitle, "The Haphazard Construction of the Human Mind." He differentiates between what he calls contextual memory and "postal code" memory. Evolution rewarded the guy walking through the forest who looked down, saw claws, heard a growl and ran for his life; the guy who waited for the stripes and teeth and whiskers before arriving at a conclusion ("Tiger!") is the guy who got eaten.
Marcus dances with atheists -- humans are both rational and irrational, and therefore, he seems to believe, there is no God -- but he's right to scoff at Americans who, when it comes to evolution, don't want to be confused with the facts. And he writes entertainingly, with jokes and pop culture references thrown in among all those revealing psychological studies. He's the kind of psych professor you wish you'd had in college.
The way our primitive and more sophisticated brain parts interact may be all kluged up, but Marcus offers a remedy: More emphasis in our daily lives on techniques of critical thinking: considering alternative theories, remembering that correlation and causation aren't the same, valuing scientific proofs over mere anecdotes. Our schools don't teach that enough, he says. But then our schools, like our brains, are built like kluges.