The Moral Animal

Because slime-mold cells reproduce asexually, the r among them is 1; they are all identical twins. From the point of view of the gene, then, there is no difference between the fate of its own cell and the fate of a nearby cell. It's not surprising that many slime-mold cells fail to reproduce, and devote themselves instead to buffering fertile fellow cells from the elements. Their neighbors' welfare, in evolutionary terms, is identical to their own. That's altruism.

Think of it: zillions and zillions of organisms running around, each under the hypnotic spell of a single truth, all these truths identical, and all logically incompatible with one another: "My hereditary material is the most important material on earth; its survival justifies your frustration, pain, even death." And you are one of these organisms, living your life in the thrall of a logical absurdity.

Still, it may be that the hallmark of the strongest, longest friendships is the depth of the shared bias; the best friends are the ones who see each other least clearly.