Fig. 4.

Individual effort magnifies the effect of inequity. Large indicates that three exchanges were required of the subject. Small indicates that only a single exchange was required. Eq indicates that both individuals received the same reward, and Ineq indicates that the partner received a better reward. (Left) Black bars show four effort conditions in which the subject received cucumber, and the partner received either cucumber also (Eq) or grape (Ineq). (Right) Gray bars show two conditions in which both individuals received grape.