10 Great Movie Twists You've Never Seen
Surprise is a brief mental and physiological state, a startle response experienced by animals and humans as the result of an unexpected event. Surprise can have any valence; that is, it can be neutral/moderate, pleasant, unpleasant, positive, or negative. Surprise can occur in varying levels of intensity ranging from very-surprised, which may induce the fight-or-flight response, or little-surprise that elicits a less intense response to the stimuli.
Surprise is intimately connected to the idea of acting in accordance with a set of rules. When the rules of reality generating events of daily life separate from the rule-of-thumb expectations, surprise is the outcome. Surprise represents the difference between expectations and reality, the gap between our assumptions and expectations about worldly events and the way that those events actually turn out. This gap can be deemed an important foundation on which new findings are based since surprises can make people aware of their own ignorance. The acknowledgement of ignorance, in turn, can mean a window to new knowledge.
Surprise can also occur due to a violation of expectancies. In the specific case of interpersonal communication, the Expectancy Violation Theory says that three factors influence a persons expectations: interactant variables, environmental variables, and variables related to the nature of the interaction or interaction variables.
(source : wikipedia)