I wanted to like this book. I just returned from the Human Behavior and Evolution Society conference in Austin, effectively hosted by Buss's department at UT Austin.
Buss spoke at the conference, and I had some big problems with what he said, but I thought I would give benefit of the doubt until I had the book in my hands.
My first big problem is the conflation of murder and war. While we can of course say that both entail violence, and that both seem to be behaviors selected for by evolution, that is all we can say. In most other aspects these behaviors are widely divergent in motivations and psychologies. Sure, sometimes men kill over women on the individual level and sometimes they take women as the spoils of war, but they also often kill all the women along with the men. While leaders may gloat about taking enemy women (as he notes), the rank and file have little choice about going to war. It is that or be exiled from the group, or see the group overrun and die with your family. Certainly over evolutionary time the choices in war were often win or die, and so women are not exactly central to the matter. One also should note that there is a huge psychological difference between killing over a woman one is, or has been, close to and killing with the hope of capturing women from an enemy group. Most critically, men go to war most often out of pro-social altruistic motives and group commitments, while many murders are anti-social selfish acts. One might just as well conflate love and lust too, if we are after confusion instead of insight.
And if Buss wants to use the term "murder" in the all-inclusive way he does throughout the book, then he must be consistent in that usage. He is not. On page 27 he states that "...the evolutionary war theory does not explain...the majority of murders..." Hmmm, do we have any evidence offered or cited that more people are murdered by individuals than die in wars? None, and I strongly doubt that it is even close to true. Certainly there is no evidence from archeology; one cannot determine if an arrowhead in a skeleton came from an external or internal foe. Again, I fail to see how conflating murder and war does anything but confuse and muddy the water, and it certainly does not help when one seems to be confused already, as Buss is.
Where else is he confused? Well, he seems to have also confused himself with someone who knows history and world events. His assertions about Saddam and Pol Pot are just wrong; Saddam was effectively in charge well before 1979, and he killed his friends, as well as enemies, in order to instil fear (inspired by Stalin's example), not to rise to power. Pol Pot never killed to rise in the ranks either, as he asserts, but was the Khemer leader from quite early on. And he did not kill to maintain control, but rather from a horribly misguided desire to create a peasant utopia (see the excellent Phillip Short effort, "Pol Pot: The History of a Nightmare").
But that is a minor issue compared to his assertion on page 63, "This is one good explanation for why, throughout human history, warriors, adventurers, and explorers come disproportionately from the ranks of men who had few alternative strategies for acquiring the perquisites of status and resources." Buss cites Daly and Wilson 2001 here, which is almost correct, except that the only Daly and Wilson 2001 he includes in his bibliography is the paper about nepotism, not the one that includes this assertion, and the real source does not go nearly as far as Buss claims. Daly and Wilson merely assert that history provides evidence that the above is true, and they say "often" where Buss claims "disproportionate." It is quite different to claim "throughout" and "disproportionate," and given that the original claims by Daly and Wilson are hardly supported, just a few historical examples given and no empirical evidence at all, it is beyond sloppy to extend this very little, literally two examples, to make such a large claim. Worse still is the fact that this assertion is just plain wrong, and in evolutionary terms it is gibberish. During the course of our evolution nearly all men must have been warriors, not just those lacking good prospects, and the book claims to be concerned with how our behaviors evolved, not with what happened in Spain in the 1500's (which is the main example Daly and Wilson give). Never mind that high status are universally expected to lead in war in band and tribal societies, and that there is a mountain of evidence from complex societies of high status being warriors throughout history. "Often" is a true statement, but we can also say that high status were "often" in these roles. "Disproportionately" "throughout" history is just plain false and baseless.
Buss's very next sentence on pg 63 is also a big problem, "And it explains why men occupying the bottom rungs of the reproductive ladder more often resort to violence." Here he cites Daly and Wilson again, this time their book "Homicide" from 1988. The problem is that this is very much not what the book says at all. In their section on status, pg 126-131, they in fact make the opposite case, showing that those who are least violent become the lowest status because of it, and are likely not to have wives, in band and tribal societies, which we commonly assume to be similar enough to how we lived during much of our evolution that we can usefully extrapolate. We do know empirically that low status are more prone to violence in highly stratified societies where the difference in incomes is great, but again the question is an evolutionary one and we know from Boehm (Hierarchy in the Forest, 1999) that it is likely we evolved in egalitarian societies and not stratified ones. Richard Wrangham has shown that the very lowest status chimps can be prone to lashing out randomly, but also that higher status chimps make them frequent objects of their aggression. If Buss's argument is that violence can increase ones status, and that this is partly why it evolved (and that is his argument), then how can it be that the lowest status are most violent? If his assertion is true, it contradicts his main hypothesis. And again, since he wants to lump war in there too, when do low status ever lead a group or nation to war? It is true that low status men are cheated on more frequently, and that men who are cheated on often become violent, but when we put all types of violence in the pot I strongly doubt that anyone has the empirical data to support this assertion, or that if the data were compiled the assertion would prove to be true. For one thing it can be quite difficult to assertain status and ones place on the reproductive ladder, a person can easily be high status within a sub-group and low status in a larger context (for example, gang leaders). And such men usually have greater reproductive success than even doctors and lawyers, at least in our society. Does that mean that doctors and lawyers are more likely to be violent than gang leaders? I would like to see that case made...
He also makes a series of wrong assertions on page 61 which I will skip going into most of. Let me just note that recent studies showed women in fact are not more attracted to men who take pointless risks, and that other empirical work has shown some of the biological reasons why men die earlier, which is unrelated to risk taking. It is absolutely not a "...cumulative consequence of dangerous competitive activities originally engaged in to show off their physical prowess." And that assertion makes no evolutionary sense; we would have plenty of opportunities to take risks for very good reasons, like getting food and going to war and so on, so the need for showing off seems to be lacking. I suggest that in fact what is happening is ritualized dominance contests between men, and the evidence is that men are the ones impressed by such actions, and they are more likely to want to be around those who engage in them.
To summarize, Buss seems not to know what he does not know. And he does not know a lot. He shows a lack of critical thinking, which is his most important task, and sloppy scholarship at best. At worst he might be making stuff up, but I tend to think that he is just getting it wrong and does not think things through very well. His basic hypothesis might be correct, it probably is, but in order to make this case convincingly we will have to continue to wait for someone with a more precise mind and a greater grasp of the material. I see absolutely no profit in tossing war in with murder, and the confusion it has caused Buss is quite visible. If this is not your field, take his assertions with a huge grain of salt. Some are right, others simply are not.