Origins and functions of positive and negative affect: A control-process view.

Carver and Scheier's cybernetic control model suggests that comparisons of the rate of progress toward the goal with a relevant criterion generate affect; when progress exceeds (falls short of) the criterion, positive (negative) affect arises.

“Carver and Scheier's (1990) cybernetic control model suggests that comparisons of the rate of progress toward the goal with a relevant criterion generate affect; when progress exceeds (falls short of) the criterion, positive (negative) affect arises”

One of the core assumptions of control theory is that individuals react negatively whenever there is a discrepancy between their standards or goals and actual outcomes.

“One of the core assumptions of control theory is that individuals react negatively whenever there is a discrepancy between their standards or goals and actual outcomes [16,34].”

Monitoring progress is highly relevant to affective well-being because progress conveys a sense of reducing the discrepancy between wanting and having-that is, approaching the goal.

“While striving to resolve such discrepancies, monitoring progress is an aspect highly relevant to affective well-being, because progress conveys a sense of reducing the discrepancy between wanting and having—that is, approaching the goal.”

Observational studies show that positive affect is linked to a greater likelihood of physical activity.

“In observational studies, positive affect is associated with an increased likelihood of physical activity[4,5,6,7] and healthy eating[5,8], as well as a lower likelihood of tobacco use [9,10].”