The issue of whether the basic nature of homo sapiens is cooperative or combative remains the subject of philosophical debate.  Even if there is no answer to this theoretical question, there can be great practical advantage to assuming that the individuals we deal with are naturally loving and caring.  If they are not acting that way, I assume that something is bothering them and if I can help them find a way out of their painful situation then they will become less combative in their treatment of me.  At the very least, this idea keeps me from taking their behavior too personally.  Often, it helps me find a way to turn the confrontation into a satisfying experience.