exteroception vs sensitiveness

exteroception and sensitiveness both are nouns.

Word	Noun	Adjective	Verb	Adverb
exteroception	Yes	No	No	No
sensitiveness	Yes	No	No	No

As nouns, sensitiveness is a hypernym of exteroception; that is, sensitiveness is a word with a broader meaning than exteroception:

exteroception: sensitivity to stimuli originating outside of the body
sensitiveness: (physiology) responsiveness to external stimuli; the faculty of sensation

Other hypernyms of exteroception include sensibility, sensitivity.

exteroception (noun)	sensitiveness (noun)
sensitivity to stimuli originating outside of the body	the ability to respond to physical stimuli or to register small physical amounts or differences
	the ability to respond to affective changes in your interpersonal environment
	(physiology) responsiveness to external stimuli; the faculty of sensation
	sensitivity to emotional feelings (of self and others)