why did the nfected only attack uninfected?
Rage gave primates uncontrollable rage, why didnt the all turn on eachother?
sharePheromones. Very common for sexual arousal in humans to copulate, so it's not far-fetched to think that an extreme retro-virus would give off pheromones to alert the senses of an infected person.
In the case of 28 Days Later, the infected bled from the mouth and sweat really hard. It could be that the infected gave off a scent due to profuse bleeding and sweat that it was pretty easy to identify the non-affected. Much like recognizing a rabid dog.
You have to remember, that even in real life, some dogs can detect cancer, and that has been documented and accepted by some that are members of the AMA. So it's highly plausible to recognize someone that is sick with the rage virus, were you infected with it, you know?
My question was why they didnt have rage towards eachother. Not how they identifed uninfected. They seemed to have selective, controlled cherrypicking rage.
The dog cancer smelling has been debunked as many times as been reported
http://scienceblog.cancerresearchuk.org/2009/02/03/can-dogs-detect-the-smell-of-cancer/
I agree it's not really explored in the film, but may be they "saw" little point in raging at each other, especially if as noted earlier, they could differentiate between infected and otherwise by sense of smell.
Mind you when you look at individual infecteds like Mailer, they do seem to rage away on their lonesome any way.🐭