The book is a summary of research findings and such on the evolutionary basis for moral behavior. (1)
The book’s best part is its argument that there’s an evolutionary basis for ethics, as opposed to theistic (God dictates) or nihilistic (no objective basis for ethics) foundations.
The downside to the book is its title and what that implies. Shermer weaves most of the writing and findings on this topic into a narrative and calls it “science.” Darwinian evolution - natural selection, mutation, adaptation, and survival - is fairly well established as science, though there is quibbling on the details. Shermer refers to this and that study to pull together his storyline, but it’s opinion (albeit, informed) stuff that can be questioned. In other words, there is plenty of room for debate, making the science claim dubious. (2)
Shermer’s overall theme is that we have been bred by evolution to be social (other-regarding) beings. Moral sentiments - sympathy, compassion, empathy; love-attachment; reciprocity-cooperation - developed to make the group cohere. Shame and guilt kept us from deviating too much from group norms, as did, especially, small group dynamics with its here-now enforcement pressures because everyone knew each other and what they were up to.
Once groups became bigger, more formalized rules were necessary to keep deviating behavior in check, and authority was necessary for enforcement. Now humans abstracted the underlying principle for moral behavior at the sentiment level. That principle, in its various iterations, was the golden rule. This in turn became the ethical universal for respecting one’s neighbor - within one’s group certainly, but Shermer extends it as a moral ought to one’s non-group, to other species, and to the earth itself.
It’s a great campfire story about who we have been and who we should become, but it's not real. What’s missing in Sherman’s account is the raw logic that flows from our evolutionary heritage. We are bred to survive. That motive force is clear enough, but, given Darwinian variation, there are two ways to do that, along with a vast continuum in between, which account for great variation about how we behave, morally, depending on the situation. (3) On one pole is other-regarding behavior where group- and self-interest are the same. This is the part that Shermer covers well. The other pole is self-interest without regard for others, which applies to intra-group as well as non-group dynamics. Both poles of behavior work for natural selection. Other-regarding motivations work because, with the group, the individual survives; without it, the individual dies. But self-only behavior within a group also survives natural selection pressures because of inherent inequalities that create dominance hierarchies and benefit differentials. In addition, there’s masking and deceit that allows individuals to free-load, cheat and pretend to be good group members when they are anything but. While, as Shermer notes, this can be detected within the small group, that dynamic breaks down in larger group settings.
This explains why we’ve had such evils (in Sherman’s sense) throughout history and across all cultures. History speaks clearly, and makes Shermer’s claim for our evolutionary future - the Golden Rule as applied to non-group, non-human species, and to the earth itself - a problematic presumption at best.
A good part of humankind is driven by motivations that are at odds with the other-regarding ethical behavior that Shermer sees. How can there be other-regarding behavior when there’s no motivation to do so? With that dynamic ever-present, it sets up a great unraveling where those individuals and groups and nations that are other-regarding must engage in defensive protection, conflict and war. (4) In other words, the golden rule works when both sides adhere, but doesn’t work at all when one side wants it all.
(1) His appendix 1 provides an excellent overview of its history.
(2) For example, Shermer repeats the claim that kin selection explains altruism (by mathematical degrees, we support our extended kin at our own expense) and then just jumps to a non-kin explanation with reciprocal altruism. Since kin altruism doesn’t work for the non-kin, Shermer and others have to import a non-mathematical, non-kin, explanation in the form of reciprocal altruism. Could it be that kin selection applies only to direct parent-child relationships in which the child is an extension of the parent’s reproductive self, and that reciprocal altruism is explained by an imperative to integrate the self with the group, which by the way, initially included largely kin and extended kin? Shermer also endorses group selection (groups compete with each other - a perspective that Darwin himself had, which supported his white-man supremacy perspective - with the stronger groups surviving, and the weaker groups dying off), despite most biologists today believing that selection at the individual level is sufficient to explain human traits. While dangerous because of the racist implications (white is superior; non-white is inferior), an argument can be made that those groups that are stronger benefit the genetic traits of individuals within those groups. But Shermer and other theorists tend to emphasize the good “cooperation” side, whereas it could be that such cooperation applies to one’s own group, not outsider groups, and that Darwin saw such cooperation as linked to “the arts of war” vis-a-vis outsiders. Shermer favorably quotes others to view religion as a form of social control, whereas viewed evolutionarily, it could be all about the need to have a comprehensive worldview that explains how the self is to survive beyond its obvious physical death, and behavioral dos and don’ts are set up conformance with doctrine. In the moral sentiments stage, Shermer says we are nature-driven, but at the larger group stage we’re driven by nurture dictates, including the golden rule. While Shermer equates nature and nurture - both have an equal effect he says - the counter argument is that cultural practices on what we do, how and why we do it reflect our biological nature? Sherman also echoes a common theme, based on scanty evidence, that small groups were egalitarian because group members could keep each other in check. It’s a claim based on the logic he uses here, but the counter logic is that it's just as likely that there was some hierarchy even abusively so, because of the inherent inequalities among individuals who exert authority, like alpha chimps, because they could get away with it. Rather than assert willy-nilly that our basic human nature is egalitarian, Sherman and others might characterize that assertion as (aspirationally?) provisional. Sherman says that science tells us facts and philosophy tells us how to act, and that there’s no linkage between fact (is) and value (ought). But doesn’t biology tell us, as science, that survival and self-interest is a fact, and doesn’t philosophy tell us how we ought to survive? (And, after all, the title of Shermer’s book implies a connection: The Science of Good, which is an ought, and Evil, which is an ought not.) Against the deterministic worldview, Shermer says we have free will because there are too many causal variables to explain why we do what we do. This is like the famous Bohr-Einstein argument, with the former saying that, because we can’t really know the behavior of quanta phenomena, free will (indeterminism) must be true. And on it goes throughout the book.
(3) Sherman writes of human nature as being one thing and he says that it is basically a good and that there’s no evil. While he acknowledges extensive variation, he smoothes over that part when it comes to moral behavior. The problem becomes apparent the way he treats good and evil. Good for him means fitting in with the group. Bad is being at odds with the group. Yet from an evolutionary point of view, good is what serves the self’s interest with or without regard for the other so that good for the self is bad for the group, or what is good for the group is bad for the self. And, Shermer passes off evil as a consequence of our situation (we all could have been Nazis he states), as if Stalin and Hitler were not, inherently, evil (bad for everyone but themselves). The fuzziness of Sherman’s unitary human nature also is clear when he refers to Brown’s laundry list of human universals that include affection, attachment, cooperation, empathy and fear - as if all humans have these in the same degree.
(4) Peace, love and harmony are all good, but shouldn't we resist self-only aggression in order to defend our self interest (i.e. the flip side of Shermer’s liberty principle, which is good)?