I have thought many times about a zombie apocalypse. I came to the conclusion that I would be generous and trusting (obviously not towards the living dead). Mainly because a zombie apocalypse I'd imagine would last a very long time as a cure would be hard to invent. So rather than being untrustworthy to friends, family and the majority of strangers would mean living alone and having no one around to talk to, to love and surly that is what builds us and is what makes us human. I also wouldn't want to live in a world where you cannot trust anyone, I wouldn't want to live in solitary; so trusting and generosity is really my only option.
Be generous with those whom you trust; friends, family, etc. However, be wary that in life-or-death situations, people change; your best friend might stab you in the back for a slice of bread if he is dying of hunger. In a world where the slightest error in judgement can be fatal, trust can be a very dangerous thing and should not be given carelessly. This is an incredibly interesting topic.
I say NO because in a world where you have the dead walking around eating people it would be dumb to have generosity! You can trust people but then again its your life on the line! Like for real i rather only trust the ones im with thats it THINK!