Survivors are people like you. Some are good, some are bad. Many Survivors will shoot on sight, just as you probably will. Some will stand their ground, only attacking if you invade their personal space. Some are friendly but don't offer anything to you. A rare few will actually be willing to trade with you. Survivors are, for the most part, a mixed bag. Some will have extremely high-quality weaponry while others have exclusively low level weapons. Some live in groups, some live alone.
This said, local conditions invite opportunism and predatory behavior so survivors are still apt to engage in murder, cannibalism and all manner of other horrific acts.
Tactical Considerations Edit
Survivors are fairly easy to kill, and generally a good source of weapons or ammo. While they usually can be dispatched with single shot to the head with most weapons, it's wise to kill them one by one using stealth to save on ammunition. If alerted of your position, hostile survivors will spray you with bullets, consuming their ammunition extremely quickly and leaving little to none left for you to loot.
Despite the weapons, supplies, and ammunition they may be carrying, it is unadvised to kill all survivors on sight due to the sanity damaging effects of murder.