Altruist

For example, if you call a wallflower an altruist, they might interpret that as being called overly image-conscious and selfishly wanting to appear too good to others.

And, of course, there is the occasional altruist who eschews earbuds altogether and generously allows others to share in the melodious sounds of his game, music or video.

Altruistic behavior, behavior that increases the reproductive fitness of others at the apparent expense of the altruist, citation in some animals has been correlated to the degree of genome shared between altruistic individuals.

The benefits for the altruist may be increased and the costs reduced by being more altruistic towards certain groups.

The moralistic altruist may want to educate or even punish a cheater.