We like to think of ourselves as self-aware, reflective beings, but psychological studies demonstrate that we’re usually overconfident in the accuracy of our own beliefs. Memory, for example, can be extremely unreliable, even when we feel certain we know what happened. Surprisingly, when we’re made aware of this, we adjust our level of confidence in ourselves only slightly. How, then, can we doubt ourselves in a rational and efficient manner to bring our beliefs closer to reality? And, just as importantly, how do we prevent ourselves from falling into the other extreme of constant second guessing? John and Ken don’t think twice with Sherri Roush from UC Berkeley, author of Tracking Truth: Knowledge, Evidence, and Science.