In psychology, positivity effect is the optimistic approach that one holds for another due to their state of liking, even if it's seemingly wrong. For example; if a friend hits, we either say that the other deserved it or that it was a defense reaction, which is, in favor of the friend; even when hitting another person is an unfavorable action.
When we ask "What motivates a person to risk his life saving another or to work long hours to achieve a particular goal?" We usually mean "Why does he behave as he does?" The term motivation, as popularly used, refers to the cause or why of behavior. Used in this sense motivation could cover all of psychology, since psychology is the study of human behavior. But we know that many aspects of psychology can be explained as the result of maturation and learning as well.
Psychologists, then, usually narrow the concept of motivation to those factors that energize behavior and give it direction. A motivated organism will engage in an activity more vigorously and more efficiently than an unmotivated one. In addition to readiness for action, motivation also tends to focus behavior-the hungry person is ready to seek food and eat, the thirsty one to drink, the one in pain to escape the painful stimuli.
Thus, central to current approaches to motivation is the notion of arousal level. Internal and external stimulation that produces too severe a change from the optimal arousal level motivates the organism to do something to restore equilibrium.