What is a flinch?

A flinch is an involuntary reaction to a sudden stimulus, often characterized by a quick movement or withdrawal in response to fear, surprise, or pain. It can be a physical response, such as flinching away from a loud noise or a sudden touch. Flinching is a natural reflex aimed at protecting oneself from perceived threats. Additionally, it can also refer to a psychological response, where someone hesitates or shows discomfort in response to a challenging situation.