Although Saxe's work has practical implications -- it may lead to early-diagnostic tests for autism, for example -- she's more interested in the big picture. Any modern investigation into how we think must illuminate why we're so bad at it. "We're totally committed to a view of how the mind works," she says -- in short, we believe people are rational -- "but most of the time, human behavior isn't based on an explicit, rational, considered decision." And our irrational tendencies are all too apparent. "[The mind] makes us make systematic mistakes over and over again, as individuals but also as societies, in how we mete out punishment and who we value, and who we think is good and who we think is bad, and how we try to change behavior for better or for worse," she says. "Maybe we can prevent ourselves from making those same mistakes again and again and again. That would be success."