Logically speaking, No.
Assuming that the average person is able to fend for themselves, there is no good reason oto band together. All it means is more mouths to feed but a lack in efficiency increase. But as we all know, humanhumans are social creatures. A complete loner would become (shocker) lonely and maybe even depressed.
Plus there's that whole morality argument, that if given the choice between good and evil(help the mother of 3 or kill her and her kids for their food), the average person will do the right thing. So from a simple mathematicallysimply mathematical perspective, there is no reason why people who can survive on their own would band together but in reality they would.
Exceptions
There are a few exceptions to the point above.
- People band together, not to defend against zombies, but to raid and kill others for their supplies.
- People band together to defend against, not the undead but the raiders mentioned above.
- The zombies are totoo powerful to reliably defend against alone (like World War Z).
- People band together for mutual skills. A prime example is Eugene in the Walking Dead; he has no physical skills, but he is very smart so it benefits less intelligent people (Abraham) to join with him.