In Peeps by Scott Westerfeld, there are two cultures described that are different then ours. One culture is the parasite positive people. They get crazy and want to eat people. They also start to despise the things they used to love. For example, if they used to love elvis, the would suddenly not be able to look at anything associated with him. This is different from our culture because we don't hate the things we love. Another culture in the book is the carriers, or people who have the parasite without the crazy symptoms. The carriers have to hunt down everyone that they infected and send them out to a treatment center in Montana. They also can't ever kiss anyone who isn't infected, or else they would infect them. Also, they have to lie to everyone about them. The book also talks a lot about different parasites and how they live. All parasites have a final host that they try to get to. Sometimes they kill other things to get there, sometimes not. Peeps is a very good book so far and I would recommed it.