Fear is an emotion induced by a perceived threat which causes entities to quickly pull away from it and usually hide. It is a basic survival mechanism occurring in response to a specific stimulus, such as pain or the threat of danger. In short, fear is the ability to recognize danger leading to an urge to confront it or flee from it (also known as the fight-or-flight response) but in extreme cases of fear ( horror and terror) a freeze or paralysis response is possible. Some psychologists such as John B. Watson, Robert Plutchik, and Paul Ekman have suggested that there is only a small set of basic or innate emotions and that fear is one of them. This hypothesized set includes such emotions as joy, sadness, and anger. Fear should be distinguished from the emotion anxiety