H. Allen Orr reviews Bob Wright's book, The Evolution of God, and captures perfectly the problem I have with Bob's beliefs concerning the apparent directionality of human moral behavior (emph. added):
Although Wright offers these ideas tentatively, it's hard to see how they're supposed to work. He has offered a materialist account of moral progress. If that account succeeds (and he thinks it does), it provides evidence neither for nor against anything transcendent. Indeed Wright's use of the word "transcendent" seems gratuitous. Consider an analogy that has little or nothing to do with morality. Economists argue that the non-zero-sum game of trade—i.e., exchange in which both sides benefit—gives rise to a direction in history: the expansion of trade and the growth of wealth. But no one is tempted to conclude that this directionality suggests a higher purpose. The invisible hand is a metaphor, not a transcendent appendage.