Propensity : an inclination or natural tendency to behave in a particular way.Scepticism : a sceptical attitude; doubt as to the truth of something.Penchant : a strong or habitual liking for something or tendency to do something.Aversion : someone or something that arouses a strong dislike or disinclination.Proclivity : a tendency to choose or do something regularly; an inclination or predisposition towards a particular thing.Antonym of Propensity is Aversion