Scientific America reports: Time and again humans have domesticated wild animals, producing tame individuals with softer appearances and more docile temperaments, such as dogs and guinea pigs. But a new study suggests that one of our primate cousins—the African ape known as the bonobo—did something similar without human involvement. It domesticated itself.

Anthropologist Brian Hare of Duke University’s Institute for Brain Sciences noticed that the bonobo looks like a domestic version of its closest living relative, the chimpanzee. The bonobo is less aggressive than the chimp, with a smaller skull and shorter canine teeth. And it spends more time playing and having sex. These traits are very similar to those that separate domestic animals from their wild ancestors. They are all part of a constellation of characteristics known as the domestication syndrome.

The similarities between bonobos and domesticated species dawned on Hare during a large departmental dinner, where he listened to Harvard University anthropologist Richard Wrangham hold forth on bonobos. “He was talking about how bonobos are an evolutionary puzzle,” Hare recalls. “‘They have all these weird traits relative to chimps and we have no idea how to explain them,'” Wrangham had noted. “I said, ‘Oh that’s like the silver foxes!’ Richard turned around and said, ‘What silver foxes?'”

The foxes that Hare mentioned were the legacy of Russian geneticist Dmitri Belyaev. In the 1950s Belyaev started raising wild silver foxes in captivity and breeding those that were least aggressive toward their human handlers. Within just 20 generations, he had created the fox equivalent of our domestic pooches. Instead of snarling when humans approached, they wagged their tails. At the same time, their ears became floppier, tails curlier and skulls smaller.

Belyaev’s experiments showed that if you select for nicer animals, the other parts of the domestication syndrome follow suit. Hare thinks that a similar process happened in bonobos, albeit without human intervention.

John Brockman, creator of Edge, presents 191 answers to the question: What is your favorite deep, elegant, or beautiful explanation?

Clay Shirky responds: Why do groups of people behave the same way? Why do they behave differently from other groups living nearby? Why are those behaviors so stable over time? Alas, the obvious answer—cultures are adaptations to their environments—doesn’t hold up. Multiple adjacent cultures along the Indus, the Euphrates, the Upper Rhine, have differed in language, dress, and custom, despite existing side-by-side in almost identical environments.

Something happens to keep one group of people behaving in a certain set of ways. In the early 1970s, both E.O. Wilson and Richard Dawkins noticed that the flow of ideas in a culture exhibited similar patterns to the flow of genes in a species—high flow within the group, but sharply reduced flow between groups. Dawkins’ response was to assume a hypothetical unit of culture called the meme, though he also made its problems clear—with genetic material, perfect replication is the norm, and mutations rare. With culture, it is the opposite—events are misremembered and then misdescribed, quotes are mangled, even jokes (pure meme) vary from telling to telling. The gene/meme comparison remained, for a generation, an evocative idea of not much analytic utility.

Dan Sperber has, to my eye, cracked this problem. In a slim, elegant volume of 15 years ago with the modest title Explaining Culture, he outlined a theory of culture as the residue of the epidemic spread of ideas. In this model, there is no meme, no unit of culture separate from the blooming, buzzing confusion of transactions. Instead, all cultural transmission can be reduced to one of two types: making a mental representation public, or internalizing a mental version of a public presentation. As Sperber puts it, “Culture is the precipitate of cognition and communication in a human population.”

Sperber’s two primitives—externalization of ideas, internalization of expressions—give us a way to think of culture not as a big container people inhabit, but rather as a network whose traces, drawn carefully, let us ask how the behaviors of individuals create larger, longer-lived patterns. Some public representations are consistently learned and then re-expressed and re-learned—Mother Goose rhymes, tartan patterns, and peer review have all survived for centuries. Others move from ubiquitous to marginal in a matter of years—pet rocks, the Pina Colada song. Still others thrive only within a subcultural domain—cosplay, Civil War re-enactment. (Indeed, a sub-culture is simply a network of people who traffic in particular representations, representations that are largely inert in the larger culture.)

With Sperber’s network-tracing model, culture is best analyzed as an overlapping set of transactions, rather than as a container or a thing or a force. Given this, we can ask detailed questions about which private ideas are made public where, and we can ask when and how often those public ideas take hold in individual minds.