Optimism is an attitude reflecting a belief or hope that the outcome of some specific endeavor, or outcomes in general, will be positive, favorable, and desirable. A common idiom used to illustrate optimism versus pessimism is a glass filled with water to the halfway point: an optimist is said to see the glass as half full, while a pessimist sees the glass as half empty. The term derives from the Latin optimum, meaning "best". To be optimistic, in the typical sense of the word, is to expect the best possible outcome from any given situation. This is usually referred to in psychology as dispositional optimism. It reflects a belief that future conditions will work out for the best. As a trait, it fosters resilience in the face of stress.Theories of optimism include dispositional models and models of explanatory style. Methods to measure optimism have been developed within both of these theoretical approaches, such as various forms of the Life Orientation Test for the original dispositional definition of optimism and the...