Approach-avoidance conflicts are choices regarding something positive, such as going out to a party, that has a negative valence (avoidance), such as getting grounded for being at the party. These decisions and the emotional state of ambivalence cause stress.
Approach-avoidance occurs when an individual moves closer to a seemingly desirable object, only to have the potentially negative consequences of contacting that object push back against the closing behavior. The negative consequences often are only imagined, so it is frequently fear that creates the problem.
Kurt Lewin (September 9, 1890 - February 12, 1947), a Jewish psychologist who is recognized as the founder of social psychology, created theories about the conflicts humans experience as: approach-avoidance, approach-approach, avoidance-avoidance, and double approach-avoidance.
Approach-avoidance conflicts occur when one goal contains both positive and negative characteristics. That is, an individual fears something that he desires. When the goal is far away, both positive and negative feelings about the goal are less strong; however, as he approaches the goal, a person's feelings about the negative characteristics arise, and he backs down, avoiding getting too close to achieving the goal. Then, as the goal is further away, he approaches again, only to have the same feelings of avoidance arise again, and he backs off, which decreases the internal conflict. Balance is achieved in ambivalence.