Each month I receive the NTSB Reporter (ntsbreporter@aol.com), which provides an abbreviated version of some of the more interesting NTSB reports that have been issued recently, along with a paragraph or two on a number of recent accidents and other stories of interest. As I read through the weather and other information available to a pilot prior to a flight that resulted in an accident, I often find myself wondering how that pilot could have made a decision to take off based on the available information. The answer may be found in a common quirk of the human mind called confirmation bias.
Confirmation bias describes our tendency to seek out and trust information that confirms what we already think or believe or want to believe, and to avoid or discount information that goes against what we believe or want to believe. This can help to explain the seemingly irrational behavior that pilots often display, especially when they have a strong motivation to depart or continue a flight. Confirmation bias can strike first in the selection of what information to access, or whether to access any outside information at all. A pilot who desperately needs to make a trip may decide that “it doesn’t look that bad” or “it seems like it’s improving” or “it looks like it’s better just east of here,” and then not access any information sources that might negate that opinion. This could explain a pilot who:
