A short, food for thought node. Downvote away if you think this belongs somewhere else.
I'd like to draw a finer distinction between various kinds of behaviors:
1. Cooperation: benefits you and benefits others
2. Altruism: hurts you and benefits others
3. Selfishness / Competition: benefits you and hurts others
4. Stupidity: hurts you and hurts others
Even if it may not be a good idea to encourage everyone to fall into category 2, if you can devise more ways for people to fall into category 1, then you will have a more successful society. The fact is category 3 often just ends up being category 4 in the long run: the Israel / Palestine conflict is a prime example.