In the movie industry almost every form of alien life involved some super intelligent or gluttonous race finding Earth and wanting to dominate or destroy us.
But how do you think the human race would seriously cope with finding or being found by another race of intellectual life?
In my opinion it's broken into 2 parts. If we are found, the human race will feel threatened. How were we found? Is their technology better than ours? Do they have an alliance of other life to go against us if we fought back? Seeing as how they are a foreign life form, there is almost virtually no chance of communication possible between our kind. Even physical gestures may be taken out of context, like the showing of teeth may be a sign of "I recognize you and my fangs are closed in respect" than a "You look delicious." The human race will probably just freeze in fear, and try to secretly organize a military force so if a single incident goes arry we will obliterate any chance of aggressive force; thus creating hostile tension for a long time.
If we found life, we would probably assume we were the dominate species and become arrogant. We would probably test them, to decide their mental capabilities and if they do not equal or surpass ours, become blue collar workers or slaves to our kind. And should they surpass us mentally but not technologically, we would probably wipe them out as a future threat.
I guess a third option of us creating a species of life from a monkey, but I doubt they would take any such race seriously. We would probably do a few tests, kill the test subjects, and then try and enhance our own intellectual capabilities.