irrationality vs insanity

irrationality and insanity both are nouns.

Word	Noun	Adjective	Verb	Adverb
irrationality	Yes	No	No	No
insanity	Yes	No	No	No

As nouns, insanity is a hypernym of irrationality; that is, insanity is a word with a broader meaning than irrationality:

irrationality: the state of being irrational; lacking powers of understanding
insanity: relatively permanent disorder of the mind

irrationality (noun)	insanity (noun)
the state of being irrational; lacking powers of understanding	relatively permanent disorder of the mind