Behavior is a function of attributes of the person (e.g., personality traits) and characteristics of the situation in which behavior occurs. This book is concerned with situational factors, particularly social ones. Groups, organizations, and institutions influence the behavior of individuals by several means, but two are of paramount importance. First, groups provide, control, and help you make sense of information. They help to define both your perception of what is (i.e., what is happening, what does it mean) and what should be (i.e., what is valued, what is good?). Second, they provide a range of rewards and sanctions that influence behavior. These two themes will be illustrated in examples throughout the remainder of this book. Groups, organizations, and institutions can be, and often are, forces for the good, but they can also create conditions that increase the likelihood that misbehavior (i.e., behavior that violates widely held beliefs and norms that describe what behaviors are good vs. bad and that have the potential to cause harm) will occur.