People should do nice things - for themselves or others - because of the positive effect it has on people, and NOT because:

* They were shamed into doing it
* They were guilt-tripped into doing it
* They were bullied into doing it
* They were harassed into doing it
* They were coerced into doing it
* 51% or more of other people are already doing it

If people cannot figure out why doing good things for themselves and others is beneficial, it should be patiently explained to them until they grasp the concept. If people seriously believe the other tactics above are right or desirable, they should have it patiently explained to them until they grasp the concept.

We are social creatures. Unfortunately, some of humanity's social strategies are less than ideal (I wanted to say "...are completely stupid", but I'm trying very hard to Do Nice Things today).