People who are depressed at the thought that all our motives are selfish are [confused]. They have mixed up ultimate causation (why something evolved by natural selection) with proximate causation (how the entity works here and now). [A] good way to understand the logic of natural selection is to imagine that genes are agents with selfish motives. [T]he genes have metaphorical motives — making copies of themselves — and the organisms they design have real motives. But they are not the same motives. Sometimes the most selfish thing a gene can do is wire unselfish motives into a human brain — heartfelt, unstinting, deep-in-the-marrow unselfishness. The love of children (who carry one's genes into posterity), a faithful spouse (whose genetic fate is identical to one's own) and friends and allies (who trust you if you're trustworthy) can be bottomless and unimpeachable as far as we humans are concerned (proximate level), even if it is metaphorically self-serving as far as the genes are concerned (ultimate level). Combine this with the common misconception that the genes are a kind of essence or core of the person and you get a mongrel of Dawkins and Freud: the idea that the metaphorical motives of the genes are the deep, unconscious, ulterior motives of the person. That is an error.
Steven Pinker