Interacting with your own kind

I wonder if David's answer about humans being more comfortable interacting with their own kind is actually more of David's feeling about humans. If robots could who or what would David be more comforable working with? Perhaps the answer is nobody. To me it was not so much what David said in response to Holloway's question but how he said the words, almost like a sneer. This antagonism between David and Holloway is shown from the beginning of the movie. It raises a question if there was some incident on Earth before the launching of the mission that involved Holloway/David? Could Weyland's programming be responsible? David should be a helpful and dutiful tool for Holloway and others to use. From the get-go we see just the opposite like two fighters sparring with each other.