There are many types of people interested in survival, from the extreme loner types to the communal types, for various reasons, etc. My own take on survival is unique in that I don't believe is possible without hope, and that you must have something to hope in to get you through to the other side. So for me its not enough that just I survive, or that even just my family survives because there may be some things of even greater value than us for which our death might be appropriate, so that an idea may survive whatever comes our way.
I think too, the argument could be made that your reasons for survival will dictate your ethics in a survival setting. I just lead a group of young single service members (joint) through a weekend adventure camp that took them into some team based survival scenarios in pretty scary situations (i.e. life & death). Most of it could be done alone, but if one person took that path, the rest of the team was in jeopardy. We quickly saw how people respond when it matters, and it said a lot about who you want by your side when it matters.