Kluge: The Haphazard Construction of the Human Mind (Houghton Mifflin; 2008)

There's a practical side too: investigations into human idiosyn

*It is sometimes said, pejoratively, that evolution is "just a theory," but this statement is true only in the technical sense of the word theory (that is, evolution is an explanation of data), not in the lay sense of being an idea about which there is reasonable doubt.

crasy can provide a great deal of useful insight into the human condition; as they say in Alcoholics Anonymous, recognition is the first step. The more we can understand our clumsy nature, the more we can do something about it.

When we look at imperfections as a source of insight, the first thing to realize is that not every imperfection is worth fixing. I've long since come to terms with the fact that my calculator is better than I am at solving square roots, and I see little point in cheering for Garry Kasparov over his computer opponent, Deep Blue, in the world chess championships. If computers can't beat us now at chess and Trivial Pursuit, they will someday soon. John Henry's fin-de-siטcle Race Against the Machine was noble but, in hindsight, a lost cause. In many ways machines have (or eventually will have) the edge, and we might as well accept it. The German chemist Ernst Fischer mused that "as machines become more and more efficient and perfect, so it will become clear that imperfection is the greatness of man." A creature designed by an engineer might never know love, never enjoy art, never see the point of poetry. From the perspective of brute rationality, time spent making and appreciating art is time that could be "better" spent gathering nuts for winter. From my perspective, the arts are part of the joy of human existence. By all means, let us make poetry out of ambiguity, song and literature out of emotion and irrationality.

That said, not every quirk of human cognition ought to be celebrated. Poetry is good, but stereotyping, egocentrism, and our species-wide vulnerability to paranoia and depression are not. To accept everything that is inherent to our biological makeup would be to commit a version of the "naturalistic fallacy," confusing what is natural with what is good. The trick, obviously, is to sort through our cognitive idiosyncrasies and decide which are worth addressing and which are worth letting go (or even celebrating).

For example, it makes little sense to worry about ambiguity in everyday conversation because we can almost always use context and interaction to figure out what our conversational partners have in mind. It makes little sense to try to memorize the phone numbers of everyone we know because our memory just isn't built that way (and now we have cell phones to do that for us). For much of our daily business, our mind is more than sufficient. It generally keeps us well-fed, employed, away from obstacles, and out of harm's reach. As much as I envy the worry-free life of the average domesticated cat, I wouldn't trade my brain for Fluffy's for all the catnip in China.

But that doesn't mean that we can't, as thinkers, do even better. In that spirit, I offer, herewith, 13 suggestions, each founded on careful empirical research:

1. Whenever possible, consider alternative hypotheses. As we have seen, we humans are not in the habit of evaluating evidence in dispassionate and objective ways. One of the simplest things we can do to improve our capacity to think and reason is to discipline ourselves to consider alternative hypotheses. Something as simple as merely forcing ourselves to list alternatives can improve the reliability of reasoning.

One series of studies has shown the value of the simple maxim "Consider the opposite"; another set has shown the value of "counterfactual thinking" — contemplating what might have been or what could be, rather than focusing on what currently is.

The more we can reflect on ideas and possibilities other than those to which we are most attached, the better. As Robert Rubin (Bill Clinton's first treasury secretary) said, "Some people I've encountered in various phases of my career seem more certain about everything than I am about anything." Making the right choice often requires an understanding of the road not traveled as well as the road ultimately taken.