‘Psychological Altruism’ is just a special case of ‘Biological Altruism’ and the “gene” for either is the most selfish of all.
Of course the concept of genes for actual characteristics all being in one-to-one correspondence with discrete sequences of DNA is simplistic, and the “gene” for something as complicated as a behaviour pattern may involve those for many different proteins along with related expression-controlling sequences, but no matter how it works, any hereditary tendency towards “altruistic” behaviour is one which is prepared to sacrifice the rest of its host’s genome in order to enhance the number of its own duplicates that are carried forward by co-specifics of the sacrificed host (even ones who are outside its host’s immediate family so less likely to share other parts of the host’s genome).
Not only this, but the wily and misnamed “altruistic gene” has often also evolved links to behaviours (manifest in humans in concepts like “morality”, “fairness” and “religion”) which ensure that the benefits of the altruistic gene actually are *not* shared with co-specifics of the host who lack that particular “gene”! (Such hosts may take risks with their own lives and relatives for the benefit of their non-related “moral peers” and/or to punish the “immoral” – possibly even including members of their own family)
Psychological vs. Biological Altruism is the latest topic at PholosophyTalk.[Note added Aug 10: Tim Dean at ‘Ockham’s Beard’ makes an interesting connection between the genetics of morality and of the immune system.]