cooperativeness vs flexibility

cooperativeness and flexibility both are nouns.

Word	Noun	Adjective	Verb	Adverb
cooperativeness	Yes	No	No	No
flexibility	Yes	No	No	No

As nouns, flexibility is a hypernym of cooperativeness; that is, flexibility is a word with a broader meaning than cooperativeness:

Other hypernyms of cooperativeness include tractability, tractableness.

cooperativeness (noun)	flexibility (noun)
the trait of being cooperative	the quality of being adaptable or variable
	the property of being flexible; easily bent or shaped
	the trait of being easily persuaded