How We Know What Isn't So: The Fallibility of Human Reason in Everyday Life

by Thomas Gilovich

Our motivations thus influence our beliefs through the subtle ways we choose a comforting pattern from the fabric of evidence. One of the simplest and yet most powerful ways we do so lies in how we frame the very question we ask of the evidence. When we prefer to believe something, we may approach the relevant evidence by asking ourselves, “what evidence is there to support this belief?” If we prefer to believe that a political assassination was not the work of a lone gunman, we may ask ourselves about the evidence that supports a conspiracy theory. Note that this question is not unbiased: It directs our attention to supportive evidence and away from information that might contradict the desired conclusion. Because it is almost always possible to uncover some supportive evidence, the asymmetrical way we frame the question makes us overly likely to become convinced of what we hope to be true.