An important concept for encouraging altruistic behavior is the idea of passing it on, that is if you do something for someone, it’s expected that they should do something similar for someone else, and preferably whatever it is, should be worth the same monetary amount. I think doing so would encourage more willingness to behave altruistically, and also discourage parasitic or narcissistic behaviors. Of course, I think the expectation for such behavior should be conveyed in a graceful and thoughtful way to not alienate or accuse anyone. The goal should be to create a habit for passing it on.