impassiveness vs stolidity

impassiveness and stolidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
impassiveness	Yes	No	No	No
stolidity	Yes	No	No	No

As nouns, impassiveness and stolidity are synonyms defined as:

impassiveness and stolidity: apathy demonstrated by an absence of emotional reactions

Other synonyms of impassiveness include emotionlessness, impassivity, indifference, phlegm, unemotionality.

impassiveness (noun)	stolidity (noun)
apathy demonstrated by an absence of emotional reactions	an indifference to pleasure or pain
	apathy demonstrated by an absence of emotional reactions