A Different Kind of Animal: How Culture Transformed Our Species by Robert Boyd (review)

A Different Kind of Animal is based on two lectures Robert Boyd delivered in 2016 at Princeton University as a part of the Tanner Lectures on Human Values series. In these lectures Boyd introduces his theory that biology and culture are both evolutionary, a topic he's been working on with Peter Richerson for three decades. Needless to say, this is a broad topic, a point brought home by the four commentators' responses to the lectures also included in the volume. All four commentators endorse the contours of Boyd's theory, and their critiques also raise valid questions: Is Boyd too reductive? Does Boyd's view of social learning and cooperation rely too much on copying others? Does he adequately define the ways that norms arise and change? Is he ignoring how individuals manipulate norms?

At the beginning of the book Boyd points out that his lectures are about human uniqueness and cumulative cultural adaptation, not the inventive capacities of individuals. He writes:

We are much better at learning from others than other species are, and equally important, we are motivated to learn from others even when we do not understand why our models are doing what they are doing. This psychology allows human populations to accumulate pools of adaptive information that greatly exceed the inventive capacities of individuals. Cumulative cultural evolution is critical for human adaptation

(p. 16).

While he mentions cumulative cultural evolution, one problem throughout the study is that his theory is based on locally based, smallscale ethnographic studies. Indeed, the real downside of the book is that Boyd never sufficiently explains how or why anyone should presume these studies could or would apply broadly. To summarize, Boyd says that social learning accounts for our remarkable success because it includes culturally transmitted information and the rules (or norms) that govern social interaction. As Boyd explains it, in relatively small groups—again, the bulk of the research presented—the benefits associated with third-party monitoring and punishment led to the evolution of a norm psychology that allowed for more extensive small-scale cooperation in early human societies. This, in his view, may have helped weakly related bands seize benefits from social exchange. Boyd additionally postulates that this in turn led to the evolution of a moral psychology, which structured the subsequent evolution of larger-scale cooperation through what he calls cultural group selection. He also stresses that human beings differ from other mammals and have become the most dominant species on Earth. "The claim here is that we can adapt to a very wide range of environments, and other animals can't, because cultural evolution gives rise to the gradual accumulation of locally adaptive knowledge at a much faster rate than genetic evolution" (p. 42). His phrasing often reminded me of the pre-Darwinian position that humans are exceptional because we are closer to God, although this clearly is not his argument.

More specifically, the first chapter argues that cultural adaptation means that people have to be moti-vated to acquire the beliefs of the people around them. Here the author endeavors to show that even the simplest hunter-gatherer societies depend on tools and knowledge far too complex for individuals to acquire on their own. Much of this argument rests on the example of lost European explorers Robert Burke and William Wills, introduced at the beginning of this chapter and threaded throughout the book. Wills's diary revealed that they were saved from starvation by nardoo cakes provided by an Aboriginal group, the Yandruwandha in Australia. Later, when Burke and Wills tried to make their own nardoo cakes to survive, they died, because they didn't have the knowledge of the Yandruwandha. Boyd attributes this to the Europeans' lack of information. In other words, according to Boyd's hypothesis, the Yandruwandha did not have some kind of instruction manual or natural history handbook of their...