receptiveness vs receptivity

receptiveness and receptivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
receptiveness	Yes	No	No	No
receptivity	Yes	No	No	No

As nouns, receptiveness and receptivity are synonyms defined as:

receptiveness and receptivity: willingness or readiness to receive (especially impressions or ideas)

Other synonyms of receptiveness include openness.

receptiveness (noun)	receptivity (noun)
willingness or readiness to receive (especially impressions or ideas)	willingness or readiness to receive (especially impressions or ideas)