insensitive vs sensitivity

insensitive is not a noun while sensitivity is a noun.

Word	Noun	Adjective	Verb	Adverb
insensitive	No	Yes	No	No
sensitivity	Yes	No	No	No

insensitive (noun)	sensitivity (noun)
	the ability to respond to physical stimuli or to register small physical amounts or differences
	the ability to respond to affective changes in your interpersonal environment
	(physiology) responsiveness to external stimuli; the faculty of sensation
	sensitivity to emotional feelings (of self and others)
	susceptibility to a pathogen

insensitive (adjective)	sensitivity (adjective)
not responsive to physical stimuli
deficient in human sensibility; not mentally or morally sensitive