Definitions

Surprise is “an emotion typically resulting from the violation of an expectation or the detection of novelty in the environment” (American Psychological Society, 2022) and represents the difference between expectations and reality. That can mean something happening that is not expected or something not happening that was expected.

Surprise can be mitigated through training, procedures, crew resource management (CRM) and experience. See the separate article on Surprise.

The startle reflex, meanwhile, is “an unlearned, rapid, reflex-like response to sudden, unexpected, and intense stimuli (e.g. loud noises, flashing lights)” (APA, 2022)