The sensitivity or insensitivity of a human, often considered with regard to a particular kind of stimulus, is the strength of the feeling it results in, in comparison with the strength of the stimulus. The concept applies to physical as well as emotional feeling. Stimulus may consist of any or all types of stimuli, including political, nationalistic, religious, physical, mental, emotional, etc. In the political sense, perception of and reaction to stimuli is often inculcated by - and for the benefit of - power holders.