Surprise

Definition

Surprise is the sense of astonishment, wonder, or amazement that is caused by something sudden or unexpected. The experience of surprise varies with the importance of the outcome, as well as beliefs about the outcome. Some formalists have offered mathematical definitions of surprise (i.e., a comparison of Bayesian priors and posteriors), but there is little consensus about a psychological definition. Some researchers treat surprise as a cognitive assessment based on the probability of an event, whereas others treat it as an emotion, on par with happiness, sadness, anger, disgust, and fear because of its unique pattern of facial expressions. If surprise is an emotion, it is an unusual one; it can be positive or negative, and it dramatically shapes the experience of other emotions.

Importance

The concept of surprise is relevant to many aspects of human behavior. Humans notice and focus on surprising events and are more likely to attend to surprising events. Surprise facilitates curiosity and learning. It also affects beliefs about other events. When a person takes an unexpected stance that violates his or her self-interest, the person's arguments are surprising and quite often more persuasive.

Surprise is a key factor in emotional life. Neurological studies show that when monkeys expect a reward, dopamine neurons fire. When monkeys get the reward, neuronal firing depends on prior expectations. Unexpected rewards lead to greater firing than expected rewards. Apparently, unexpected pleasures are more rewarding than expected ones.

What Makes Something Unexpected?

If surprise depends on sudden or unexpected events, what makes something unexpected? An unexpected event is a low-probability event. Surprise usually follows the event, but it can also be anticipated. However, the intensity and duration of surprise may be harder to forecast than the valence of a future event.

An unexpected event may be an unfamiliar event. A tourist who travels to Hawaii may be surprised to see 30-foot waves, despite the fact that such waves are common during the winter months and familiar to local inhabitants. An unexpected event may also be a novel event. Most people expect swans to be white, so a black swan is unique and rare.

Unexpectedness depends on the ease with which a person can imagine an event. Some people are more surprised to draw a red ball at random from an urn containing 20 balls, 1 of which is red, than to draw a red ball from an urn with 200 balls, 10 of which are red. Although the two events are equally likely, the first event can happen in only one-way, whereas the second event can happen in 10 different ways.

Unexpectedness also varies with the ability to imagine other events unfolding. Some people are more surprised to select a red ball at random from a jar with 1 red ball and 19 blue balls than to pick a red ball from a jar with 20 balls, each a different color. In the first case, the blue ball is the only referent, but in the second, there are many referents. In a similar fashion, a negative event is often more surprising, and more tragic, if there were many ways it could have been avoided than if there was only one way.

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