What does this show about how life changes when mere survival is a struggle?

It shows that we as humans tend to do anything we have to do to survive. Whether its kill each other and turn to cannibalism if were hungry. For example in the book "Night" when Eliezer is in the camp these people will sit back and watch as their friends, family, etc. are being killed and beat just so they don't get killed or beat. So we do whatever we have to do to survive, because we are that selfish. It changes our life by making us very selfish and not caring about one another and doing WHATEVER we have to in order to survive.