Learned helplessness predicts that persons who develop a belief that they cannot influence or adjust to their circumstance of separation from home will become depressed and make fewer attempts to change that circumstance. Control beliefs theory predicts that negative affect is most likely in persons who perceive personal incompetence in the separation environment (e.g., poor social skills at a summer camp or university) and who perceive contingency uncertainty (e.g., uncertainty about whether friendly behavior will garner friends). Although these are not the only broad etiologic theories that inform homesickness, note that both theories hinge on control, the perception of which "reflects the fundamental human need for competence" (Skinner, 1995, p. 8). This is particularly relevant to coping, because people's choice of "how" to respond to a stressor hinges partly on their perception of a stressor's controllability.