Altruists are angry people, Michael Strong explains:
Are altruists occupationally prone to anger? Well, it turns out that they are, in fact, biologically inclined to be angry and punitive toward those who they perceive to be not being helpful.Evolutionary psychologists believe that status is correlated with perceived community altruism because in part it was in our evolutionary interest to prevent free riders…
We are willing to punish those who do not contribute to collective action even at a cost to us, another finding that is inconsistent with rational choice…
Thus, the very fact that we have moral impulses to support the public good is necessarily intertwined with the fact that we have moral impulses to punish those who do not (and to punish those who do not punish those who do not, and so on)…
This instinct is especially harmful when used to punish those who are perceived not punishing free riders. This is the source of the bigotry against market economics among the do-gooders: It is believed that those who describe the positive outcomes of free enterprise are not doing their job to behave punitively toward free riders, and that therefore they, too, must be punished.
But it’s worse than that, Arnold Kling says:
You can signal that you are an altruist not by engaging in altruistic acts, but simply by expressing a desire to punish others. For example, by taking away AIG bonuses, you do a great deal to signal altruism, even though the actual social gains from taking the bonuses away are miniscule (the gains may even be negative).
Kling has more to say about deception and signaling. Read the whole thing.