Fear is an emotional response to a perceived threat. It is a basic survival mechanism occurring in response to a specific stimulus, such as pain or the threat of danger. Some psychologists such as John B. Watson, Robert Plutchik, and Paul Ekman have suggested that fear is one of a small set of basic or innate emotions. This set also includes such emotions as joy, sadness, and anger. Fear should be distinguished from the related emotional state of anxiety, which typically occurs without any external threat. Additionally, fear is related to the specific behaviors of escape and avoidance, whereas anxiety is the result of threats which are perceived to be uncontrollable or unavoidable. Worth noting is that fear almost always relates to future events, such as worsening of a situation, or continuation of a situation that is unacceptable. Fear could also be an instant reaction, to something presently happening.<+The Old English term fear meant not the emotion engendered by a calamity or disaster, but rather the event itself. The first recorded usage of the term "fear" with the sense of the “emotion of fear” is found in a medieval work written in Middle English, composed circa 1290. The most probable explanation for the change in the meaning of the word "fear" is the existence in Old English of the related verb frighten, which meant “to terrify, take by surprise”.