tendency vs negativity

tendency and negativity both are nouns.

Word	Noun	Adjective	Verb	Adverb
tendency	Yes	No	No	No
negativity	Yes	No	No	No

As nouns, negativity is a hyponym of tendency; that is, negativity is a word with a more specific, narrower meaning than tendency:

tendency: a characteristic likelihood of or natural disposition toward a certain condition or character or effect
negativity: (chemistry) the tendency of an atom or radical to attract electrons in the formation of an ionic bond

Other hyponyms of tendency include heterosis, hybrid vigor, buoyancy, electronegativity, stainability, desire.

tendency (noun)	negativity (noun)
a characteristic likelihood of or natural disposition toward a certain condition or character or effect	characterized by habitual skepticism and a disagreeable tendency to deny or oppose or resist suggestions or commands
an attitude of mind especially one that favors one alternative over others	(chemistry) the tendency of an atom or radical to attract electrons in the formation of an ionic bond
an inclination to do something	an amount less than zero
a general direction in which something tends to move	the character of the negative electric pole