Less (Information) Is More

When Benjamin Franklin's nephew Joseph Priestley found himself stumped by a complex life decision, he wrote his sage uncle for advice. In his 1772 letter of reply, Franklin described his own method for reasoning out complex problems, which he called "moral algebra." Divide a sheet of paper in half, he counseled his nephew, and make an exhaustive list of pros and cons. Then, over a couple days, weigh the pros and cons, and when a pro and a con seem of equal weight, strike them both out. What is left in the balance is the best answer.

Such "balance sheet" calculation is still taught today as the most logical and systematic method for dealing with many of life's complexities. Kids are counseled to choose colleges and careers this way, and managers similarly deliberate the pros and cons in important business decisions; some people are even methodical in matters of the heart.

But is moral algebra really the best method for decision making in today's dizzyingly complicated world? Or is there virtue in simplicity for many life choices? A growing number of psychologists are questioning the soundness of Franklin's method, and its modern iterations, including data-heavy calculations by increasingly powerful computers.

One of the leading challengers to the dogma of decision making is psychologist Gerd Gigerenzer, of the Max Planck Institute in Germany, whose new book "Gut Feelings" collects a convincing body of evidence for the power of hunches over laborious data crunching. Hunches, gut feelings, intuition—these are all colloquial English for what Gigerenzer and his colleagues call "heuristics," fast and efficient cognitive shortcuts that (according to the emerging theory) can help us negotiate life, if we let them.

Consider the "take the best" heuristic. "Take the best" means that you reason and calculate only as much as you absolutely have to; then you stop and do something else. So, for example, if there are 10 pieces of information that you might weigh in a thorough decision, but one piece of information is clearly more important than the others, then that one piece of information is often enough to make a choice. You don't need the rest; other details just complicate things and waste time.

Gigerenzer has demonstrated this in the laboratory. He asked a large number of parents to consider a scenario in which their child wakes up after midnight short of breath, wheezing and coughing. They are told that a doctor could make a home visit in 20 minutes; it's a physician they know but don't like all that much, because he never listens to their view. Alternatively, they could take their child to a clinic 60 minutes away; the doctors there are unknown, but good listeners by reputation. Which to choose?