Frightened of your own shadow? Worried about lone gunmen and psycho killers? Pinker (Psychology/Harvard Univ.; The Stuff of Thought: Language as a Window into Human Nature, 2007, etc.) encourages readers not to fret so much.
Recognizing that the world can be a dangerous place, the author sets out as his overarching thesis the fact that violence has steadily declined in human society over the generations—“today we may be living in the most peaceable era in our species’s existence.” For those who consider humans to be simply well-armed chimpanzees, Pinker argues that there would seem to be nothing innate about “coalitional violence”—that is, the savage raiding that so characterizes chimpanzee society on one hand and what ethnologists used to call primitive human societies on the other. Yet, he adds, neither is there much reason to believe that we evolved to be peaceniks on the putative model of bonobos, who, in nature, turn out not to be the hippies of the primate world but who nonetheless cause less mayhem than their (and our) chimp relatives. In other words, our behavior is more situational and provisional than hard-wired, for which reason, as Pinker writes, the rate of violence (at least, of the non-coalitional sort) in most parts of the world is steadily declining. As evidence, he cites the steady disinvestment of many world powers in military enterprises, as well as the complex statistics in rates of death in warfare in state and nonstate societies (for the Aztecs, about 250 per 100,000; for America during the Vietnam era, about 3.7 per 100,000). Pinker ranges widely, citing the literature of neuroscience here and the poems of Homer there, visiting vast databases of statistics while pondering the wisdom of Thomas Hobbes’ conception of human life as “nasty, brutish, and short,” and analyzing such weighty matters as “the adaptive logic of violence” and “pathways to self-control.” Classic Pinker, jammed with facts, figures, and points of speculative departure; a big, complex book, well worth the effort for the good news that it delivers.