Norsemaiden
barbarian
the actor usually has no idea he is benefiting himself, and is surely not taking the action for that reason.
Certainly the actor may have no idea that he is benefitting himself. When someone donates money to starving Africans, for example, they are very likely feeling that they are performing a selfless act - yet of course it is not so because they do get the benefit of feeling they have done something positive. And if they feed their own starving children they have the additional benefit of helping copies of their own genes.
It is insane to deliberately do something that thoroughly disadvantages you and doesn't even give you a positive feeling about what you do. That most likely only ever happens by accident.