Fear of mice avoid a mouse, showing there may be some basis for this belief. It is not known why elephants should react in this way, though there are several theories. Regardless, elephantine murophobia remains the basis of various jokes and metaphors. The classical board game Dou Shou Qi has the Rat kill an Elephant: as multiple editions of the rule book mentions that the Rat would crawl into the Elephant's ears to gnaw into its brain: but this is considered to be a folk tale. Gertrude of Nivelles is the patron saint of murophobia, and is also invoked against rats and mice
Abnormal psychology A predisposing cause is an underlying factor that interacts with the immediate factors to result in a disorder. Both causes play a key role in the development of a psychological disorder. For example, high neuroticism antedates most types of psychopathology. The standard abnormal psychology and psychiatry reference book in North America is the Diagnostic and Statistical Manual of the American Psychiatric Association. The current version of the book is known as DSM-5. It lists a set of disorders and provides detailed descriptions on what constitutes a disorder such as Major Depressive Disorder or anxiety disorder. It also gives general descriptions