This is why I don't believe in alien contact with humans. It would be this scenario:
Alien: "Greetings! We bring you the ageless knowledge of peace, enlightenment and..."
Humans: "AAAGH! Something we don't immediately recognize! KILL IT! KILL IT!"
Alien: "But..." (dies in hail of rocks and bullets)
Don't be a leftist by insisting that people are equal.
It depends on the human the alien encounters -- all humans are not equal, and if you loathe humans, loathe the dumb ones not all of us equally.
Goethe, upon encountering an alien, would figure it out.
Your average food service worker would not.
This is why we worry when bad things happen to intelligent people, but don't care when 20,000 serfs perish in a flood. They're of lower value to humanity, nature and the cosmos.