spontaneity vs naturalness

spontaneity and naturalness both are nouns.

Word	Noun	Adjective	Verb	Adverb
spontaneity	Yes	No	No	No
naturalness	Yes	No	No	No

As nouns, naturalness is a hypernym of spontaneity; that is, naturalness is a word with a broader meaning than spontaneity:

spontaneity: the quality of being spontaneous and coming from natural feelings without constraint
naturalness: the quality of being natural or based on natural principles

spontaneity (noun)	naturalness (noun)
the quality of being spontaneous and coming from natural feelings without constraint	the quality of being natural or based on natural principles
	the likeness of a representation to the thing represented
	the quality of innocent naivete