Through our global perspective, we make predictions how people will react to different situations. We also attribute underlying motivations, intentions, and thoughts to what they do and say. Furthermore, if someone does something that’s inconsistent with what we expect, we try to force fit their behavior into our global perspective. So, if we have a negative perspective about someone and that person does something good, we’re pretty sure they had ulterior motives that aren’t so good. People either get or don’t get the benefit of the doubt, depending on how we view them in general.
This is all falls under Attribution Theory, developed by Psychologists to explain how people interpret the behavior of others. As it’s basic tenets, Attribution Theory holds that there are two sets of factors people consider for attributing motives — they can do so from the disposition or outward characteristics of a person, or they can rely on external or situational factors — one’s hairstyle is an example of the former, while courtroom evidence of the latter.