aggression vs aggressiveness

aggression and aggressiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
aggression	Yes	No	No	No
aggressiveness	Yes	No	No	No

As nouns, aggression and aggressiveness are synonyms defined as:

aggression and aggressiveness: a feeling of hostility that arouses thoughts of attack

aggression (noun)	aggressiveness (noun)
violent action that is hostile and usually unprovoked	the quality of being bold and enterprising
deliberately unfriendly behavior	a natural disposition to be hostile
the act of initiating hostilities	a feeling of hostility that arouses thoughts of attack
a disposition to behave aggressively
a feeling of hostility that arouses thoughts of attack