AURA SENTIERO

A vampire's morality has a direct impact on her bearing -- a feeling the Kindred unconsciously projects. The greater the vampire's Humanity or Path rating, the stronger this tendency is. For example, vampires on Humanity have a bearing of normalcy; the humane connection that such vampires hold keeps them from seeming strange and terrifying to mortals.

Generally, a vampire's bearing has little or no direct effect on her nightly activities -- it's only a vague impression. Very high or low morality ratings impose a bonus or penalty to specific rolls associated with the character's bearing -- for Humanity, the bearing modifier affects Social rolls for appearing normal and winning sympathy. These modifiers can affect rolls used for Disciplines, where relevant. Paths of Enlightenment have their own bearings, which are listed with each Path description.
(Corebook V20 pag. 310)

The Storyteller is free to decree that characters of low Humanity/Path (4 or less) occasionally act according to various urges and impulses that must be resisted with Conscience/Convinction rolls or Willpower expenditure. This is the crux of Vampire — how closely can the character walk with the Beast before it drags her into damnation?
(Corebook V20 pag. 311)