“Snap Judgments – Risks and Benefits of Heuristic Thinking” There are two important systems at work in human thinking and decision making. One is a highly reflective judgment process (referred to often as ‘System Two’) and the other (‘System One’) is an heuristic process that relies on previous learning and sensory input. Both systems are at work all the time. Both systems are valuable to survival, and they check and balance each other when humans think well.  Both need to be monitored for error to prevent poor decision making and lost opportunity. This material describes System One and cautions against common errors that occur in System One thinking.  These pages are extracted from THINK Critically, Facione & Gittens, Pearson Education (3rd. edition) and offered here with the author’s permission.