I was really looking forward to reading this book. One of the questions that keep haunting me is: how is it possible that the same species that David Livingston Smith called (rightly) "The Most Dangerous Animal" (dangerous for other members of its own species, that is !) is at the same time one of the most cooperative species of the world, surpassed only by eusocial insects and maybe naked moles? This book, I hoped, would give me some hint to solve this conundrum. And it did.
But first a caveat: When the book finally arrived, I leafed through it - and was tempted to send it back immediately. Mathematical formulas and equations, lots of, crawling like little black spiders on every second page! Math makes me sick. I haven't got any mathematical education beyond the rule of three (and I'm not proud of it, believe me), so I tackled the book with more trepidation than hope. Unfortunately, the style also lived up to my worst fears: hardcore scientific prose you normally expect in journals like "Behavioral Ecology and Sociobiology" or "Journal of economic Theory". I never read these publications, a trait I share with the majority of Amazon customers, I guess. So I just kept skipping the parts with the math and tried to make sense of the rest.
And now for the good news: The rest does make sense. It gave me some hints to look for an answer to the maddening ambivalence of human nature I mentioned above. The hint, in a nutshell, is something like: Take confrontation and cooperation as two sides of the same coin. The term Bowles/Gintis coined for it is "parochial altruism".
There are in principle two ways to explain human altruism.
(A) Altruism is only skin-deep. Selfishness always lurks behind nice appearances. For instance Trivers' "reciprocal altruism", a misnomer, because no genuine altruism is involved. People, according to this approach, expect (sub-consciously) to be repaid sooner or later. If somebody helps a total stranger, with no prospect of being repaid, this theory explains it as a "Big Mistake". Because humans spent most of their history living in small groups, based on kinship, the human mind even today, in an anonymous situation, acts as if it still were in the pleistocene, helping not some stranger but a relative or some guy he or she will probably meet again sooner or later. Scrath my back, and I'll scratch yours. See you. Genuine altruism today therefore would be a kind of misfiring in a situation unknown to the old mental moduls that still govern our behavior. Bowles/Gintis show that this "Big-Mistake-Hypothesis" cannot be true, because even in the Pleistocene, humans had plenty of contact with strangers. The picture of small and demographically closed bands of stone-age people is a myth.
(B) Bowles/ Gintis argue that altruism can be genuine. But if altruism is defined as a behavior that increases the fitness of the recipient and that is costly for those who practise altruism - how can it spread ? Because evolution is a game that dispenses with rules others than natural laws, being nice has to pay off, or it will disappear. What, according to Bowles/Gintis, is the mecanism that assures the success of altruism ? Their answer is: group-selection. The whole argument of the book, as far as I can see, hinges on the question whether group-selection, or multi-level-selection, as it is often called today, works or not. That's the point where the mathematical models come in, and where I drop out.
The prerequisite for group-selection being effective is that selection within groups is reduced compared with selection between groups. The picture that emerges from the modeling is that groups who managed to reduce internal strife and competition, by inventing and promoting cultural "leveling mechanisms", will act as units of selection and will outcompete groups with more selfish members. The competition, suppressed or reduced within groups, will increase between groups. Humans developed a special kind of groupishness: Being unconditionally altruistic towards their own people, being even eager to punish freeriders of the own group, even if the punishment is costly for them, while at the same time acting xenophobically towards other groups. The parochial quality of unconditional (not reciprocal !) cooperation is the necessary condition of genuine altruism to prevail.
Unfortunately, I'm in no position to decide whether the scientific arguments forwarded by Bowles and Gintis, based on mathematical models, hold true or not. On this question, I declare myself incompetent. But I'd say that everybody who is interested in human evolution should read this book, even without competence in higher math, because the idea is fascinating that in human history it was groups more than individuals who were selected for or against. And that is was culture that formed groups in a way to make them act as units of selection. I think that culture and its group-formimg force is the part of the picture that Dawkins and the gene-centered view of evolution missed.
Just one final remark: Herbert Gintis is one of the top reviewers of Amazon, and it's always a pleasure to read his commentaries. They are written in a clear, accessible style. If only this book was written a bit more like his reviews. My wish is: keep the jargon to the journals. Books like these are for interested layfolks. The math may be essential for the argument; the jargon certainly isn't. Therefore only four points.