[jstanley]

When it's a duty that others have imposed on you, it becomes a form of oppression rather than free action. Instead of feeling good about helping everyone, you feel bad about being bossed around by everyone.

The "socially-enforced expectation" is the same. You know whether you're doing something altruistically for the common good, or whether you're doing it because if you don't others will try to shame you.

[AnthonyMouse]

Moreover, with a culture of altruism, there is no principal-agent problem. You want to help others, so you do.

As soon as you introduce coercion, the type of people motivated by power are attracted to the power to coerce and corruption takes root.