Not necessarily. Psychological studies show primates, including chimps and humans, are far more "successful" (become leaders, get more mating opportunities, get fed) when they cooperate with one-another. Animals (and by extension, people) who act in a selfish manner and refuse to cooperate with the rest of the group most often find themselves to be outcasts and end up far less successful. To make a long story short (too late), for me to get mine I have to make sure you get yours too.
Cooperation is good. It can lead to success. On the other hand, so can lying, stealing and murder.
Consider our last president. Consider the people who voted for him on the presumption he will get them things that they never earned.
You can argue they cooperated. Of course you can argue that conspiracy is cooperation, too.
My theology concerning human nature is fairly conservative. We are fallen and need a savior.
Otherwise known as "enlightened self-interest."