if you are a thinker, it is easy to overanalyse and generalise because the information available to us is never in itself complete but only a part of the whole, so its a natural attempt by the brain to make sense of the world around us. it is equally just as easy to end up with a distorted perception which would prove to be a vicious cycle especially when we dont have the facts and we make up assumptions, presumptions leading to prejudices and distortion of thought....therefore...analysing and more analysing until one's brain is driven insane and then our behaviour becomes irrational and not in line with the expected norm.
Therefore, in response, I tend to get a balance, keeping tabs...getting a little focused and be a little systematic, bearing in mind thought that sometimes there are things not worth analysing, but others demand an attempt of it, even if just a little. Taking things at face value - well, depending on your character and the other person's character and motivations or biases...i'd say tread carefully.
Self-serving biases and motivations in Psychology studies can be interesting (e.g. actor/observer effect as well as fundamental attribution errors). See http://www.youtube.com/watch?v=AkWTCXDCVvc