In 2010, my two Harvard mathematician colleagues and I dismantled kin-selection theory, which was the reigning theory of the origin of altruism at the time.
Countries that intervene militarily rarely do so out of pure altruism.
Altruism is innate, but it's not instinctual. Everybody's wired for it, but a switch has to be flipped.
In brief, egoism in its modern interpretation, is the antithesis, not of altruism, but of idealism.