mentality vs mental capacity

mentality and mental capacity both are nouns.

Word	Noun	Adjective	Verb	Adverb
mentality	Yes	No	No	No
mental capacity	Yes	No	No	No

As nouns, mentality and mental capacity are synonyms defined as:

Other synonyms of mentality include brain, brainpower, learning ability, wit.

mentality (noun)	mental capacity (noun)
mental ability	mental ability
a habitual or characteristic mental attitude that determines how you will interpret and respond to situations