“I’m certain we can’t answer that question,” says Michael Gervais. “At the world-class level, where talent differences are marginal, we estimate that 90 percent of success for elite performers is mental—yet this is the one measurement milestone we haven’t hit. We don’t know how to measure thought. What is it? Where does it begin? Where does it go? Can we track it? Can we track its effects? What’s an accurate picture of its total impact on biology? Until we know these things, psychology remains a fuzzy science.
