Re: World War Z ratings/spoilers
There's no indication of anything like that in the film, and I highly doubt they'll go that way in the sequels. It's implied to just be a instinctual thing, which is silly, but whatever. I'd chalk it up to silly pseudoscience on the part of the writers before I start concluding that that was all part of an elaborate plan to show that the zombie virus is some kind of super-intelligent malevolent entity.
'First Contact' is the tale of a man who just wants to cash in on his creation so he can get wasted on an island full of naked women, but his fans keep insisting that he's a saintly visionary who has profoundly altered the world. AKA - 'I Don't Want to be a Statue: The Gene Roddenberry Story.'