Fear of mother-in-law. (Novercaphobia)
According to preparedness theory, evolutionary processes from the past and conditioning processes acting on an individual in the present, produce phobia. Those who advocate the theory believe that it explains the non-random distribution of phobic fears. Indeed, some studies have shown that it is relatively easy to induce physiological 'fear' responses (measured by skin conductance tests and heartbeat rate) to stimuli that are commonly involved in phobias.