Balian of Ibelin: You go to certain death.
Hospitaller: All death is certain. I shall tell your father what I've seen you become.
--Kingdom of Heaven
Although confidence and optimism are sometimes defined similarly, it can be useful to view them as unique constructs. Confidence is the extent to which individuals think they know outcomes with certainty.
High levels of confidence are associated with strong belief that particular behavior or events will result in a particular outcome. Across the probability spectrum associated with various possible outcomes, a highly confident person assigns high probability to a narrow set of outcomes. Thus, a person who is highly confident that it will rain today sees little chance of other possible outcomes. A person who is less confident would spread probability of other outcomes (sunny, partly cloudy) in a more balanced fashion.
In this sense, confidence shares much in common with expectation, prediction, and conviction. The opposite of confidence in this sense can be seen as humility, i.e., the admission the one does not know how things will turn out with any great certainty.
It is, of course, possible that confidence can be misplaced. In fact, there is a burgeoning literature suggesting that people tend to be "overconfident"--i.e., they mistakenly assign higher probabilities to outcomes than they should. This is particularly true in the case of extreme events such as winning the lottery or managing catastrophes.
Optimism, on the other hand, is the extent to which individuals desire that events will unfold in a particularly way. While it may seem similar at first glance, optimism differs from confidence. An individual may be confident about a negative outcome such as death from a disease but optimistic about the process along the way such as living life more fully during that period than otherwise.
Degree of optimism might also influence a person's chances for 'beating the odds.' Optimistic people are more capable to recognizing opportunities and experimenting with ways that might alter their condition--even conditions deemed to have a high likelihood of occurring. People with less optimistic stances are less likely to recognize or pursue such courses of action.
It is possible, then, for a person to be both 'realistic' (recognizing high likelihoods associated with particular outcomes) and 'optimistic' (searching for ways to positively influence the probability spectrum).
In this sense, optimism shares much in common with hope. The opposite of optimism in this sense is pessimism or fatalism.
While confidence can be misplaced as discussed above, is the same true for optimism? We'll consider in a future post.