Physicians often make errors – up to one in five patients are misdiagnosed. The degree of confidence a physician has in his diagnosis does not necessarily correlate with the accuracy of the diagnosis. People are overly deferential to experts when making decisions and are loathe to challenge them. Anxiety, stress and fear can distort our choices. Bias strongly affects how we use information – we tend to focus on information that agrees with the outcomes we want. Often, it’s the information that challenges our existing opinions or wishful desires that provides us with the greatest insights.