Disappointment is the feeling of dissatisfaction that follows the failure of expectations to manifest. Similar to regret, it differs in that the individual feeling regret focuses primarily on personal choices contributing to a poor outcome, while the individual feeling disappointment focuses on outcome. It is a source of psychological stress. The study of disappointment—its causes, impact and the degree to which individual decisions are motivated by a desire to avoid it—is a focus in the field of decision analysis, as disappointment is one of two primary emotions involved in decision-making.
Disappointment, and an inability to prepare for it, has also been hypothesized as the source of occasional immune system compromise in optimists. While optimists by and large exhibit better health, they may alternatively exhibit less immunity when under prolonged or uncontrollable stress, a phenomenon which researchers have attributed to the "disappointment effect". The "disappointment effect" posits that optimists do not utilize "emotional cushioning" to prepare for disappointment and hence are less able to deal with it when they experience it. This disappointment effect has been challenged since the mid-1990s by researcher Suzanne C. Segerstrom, who has published, alone and in accord, several articles evaluating its plausibility. Her findings suggest that, rather than being unable to deal with disappointment, optimists are more likely to actively tackle their problems and experience some immunity compromise as a result.
In 1994, psychotherapist Ian Craib published the book The Importance of Disappointment, in which he drew on the works of Melanie Klein and Sigmund Freud in advancing the theory that disappointment-avoidant cultures—particularly therapy culture—provides false expectations of perfection in life and prevents people from achieving a healthy self-identity. Craib offered as two examples litigious victims of medical mistakes, who once would have accepted accidents as a course of life, and people suffering grief following the death of a loved one who, he said, are provided a false stage model of recovery that is more designed to comfort bereavement therapists than the bereaved.
In a 2004 article, the journal Psychology Today recommended handling disappointment through concrete steps including accepting that setbacks are normal, setting realistic goals, planning subsequent moves, thinking about positive role models, seeking support and tackling tasks by stages rather than focusing on the big picture.
While earlier developers of disappointment theory focused on anticipated outcomes, more recent examinations by Philippe Delquié and Alessandra Cillo of INSEAD have focused on the impact of later disappointment resulting when an actual outcome comes to be regarded negatively based on further development; for example, if a person receives higher than expected gains in the stock market, she may be elated until she discovers a week later that she could have gained much more profit if she had waited a few more days to sell. This experience of disappointment may influence subsequent behavior, and, the analysts state, an incorporation of such variables into disappointment theory may enhance the study of behavioral finance.
Disappointment" is, along with regret, measured by direct questioning of respondents.