One good reason. How to make decisions.

The author of Gut Feelings: The Intelligence of the Unconscious (as quoted in Newsweek) argues that we make the best decisions by using one good reason instead of weighing all the pros and cons:

In every case, one good reason has proven superior to data-greedy mathematical equations in making the best choices.

The example he gave was a parent whose child wakes up wheezing in the middle of the night.  One doctor they know can come to the house in 20 minutes but he's not a good listener or they can drive 60 minutes to an unknown doctor who's known to be a good listener.  Although there are four pieces of information, most parents make their decision based on one piece of information: whether or not the doctor is a good listener.  The author argues that the gut feel decision based one piece of information is better than the decision that could have been made by weighing all four.