To the Editor:
The Science Times article, "In a Helpless Baby, the Roots of Our Social Glue," posits a false choice between two possible human evolutionary drivers: cooperative baby-rearing for in-group success, or social cohesion to overpower out-group rivals. Both forces could drive human evolution, and there may be little difference between them.
The article portrays Dr. Hrdy as supporting some version of the peaceful Noble Savage myth, and denying violence as a driving force. Scholarship such as that in the book "War Before Civilization" demonstrate otherwise, that violence between hunter-gatherer groups is and was much higher on a per capita basis than in large, organized societies.
Dr. Hrdy may be referring to evidence of a genetic bottleneck in human prehistory in order to claim small populations didn't need to fight, but that one bottleneck doesn't mean populations were always below the carrying capacity of the habitat they used. Basic biological law known since Darwin states that species will quickly expand populations until they overfill their habitats, and then something decides which groups will survive. It was almost certainly violent choices in the past, but hopefully our big brains and modern tools give us a different options for the present and future.
To be fair to Hrdy, she's apparently referring to ancient hominids who might have been genetically/culturally different from modern hunter-gatherers, but I still doubt she's right. And when she claims "the average population size during the hundreds of thousands of years of human evolution that preceded the Neolithic Age may have been around 2,000 breeding adults," I find it hard to believe a population that small could last that long and not wink out. Wiki thinks "as long as" 100,000 years, still an unlikely long time but short compared to hominid evolution. Even if it's true, that small population has to be kept small by something other than competition for habitat or intra-species violence, in order to resurrect the Noble Savage.
Anyway, I've been meaning to blog about the War Before Civilization book. It's excellent, if somewhat depressing about our past. Peace is possible without civilization, but it's not easy to keep. Afarensis did a great post about the book a while back for more info.
(And yes, this post falls into the "I read a book and now think I know more than an expert in the field" category. Oh well.)
UPDATE, Jan 2010: more evidence in support of Hrdy's position and against mine, this time that hominids had incredibly small populations dating back 1.2 million years. They also claim that chimps and gorillas had similarly-small populations despite the radically different habitat that they use. Weird. I'm not convinced, yet.