Culture, Society, & Behaviour

Tracking our cultural DNA

January 01, 2011

To mark the end of the 350th anniversary year of the founding of the Royal Society of London, a special website was launched listing the 12 most exciting areas in science today. One of them is the evolution of culture. A leading expert on the subject is here at SFU. Mark Collard applies biological techniques to anthropological data to understand how we inherit cultural information from our ancestors.

Physically, humans have not changed much in the last 200,000 years. However, the amount of cultural change over that time period is astonishing. Consider literacy as an example. Only 500 years ago, books were rare and few people could read or write. Today literacy is ubiquitous. The situation with computers is even more remarkable. The first personal computers appeared in the mid-1970s. Thirty-five years later, PCs have become so powerful that their use is now the norm in many countries. Recent surveys suggest that almost half of all Canadians have a Facebook account.

How can culture evolve so much faster than biology? Does such rapid cultural evolution affect biological evolution? How are cultural traits passed on from one generation to the next, and among peers? Surprisingly, while these questions were posed as early as the 1880s, only recently have we begun to find the answers. One of the world’s leading thinkers in this area of research is Mark Collard, SFU’s Canada Research Chair in Human Evolutionary Studies.

The media is fond of pitting Nature vs Nurture when reporting on human behaviour, but Collard doesn’t see it that way. “We phrase it in terms of culture versus biology, but culture is part of our biology, and in fact it’s the key reason we’ve been so successful as a species,” he says. “There’s a better way of thinking about culture and biology,” Collard continues. “There are grounds for viewing genes as units of information rather than physical entities. And we can think about culture in similar terms. Culture is basically a set of rules for how to behave. So, humans can be regarded as having two systems of information inheritance—a genetic one that is based on reproduction, and cultural one that is based on social learning. These systems run in parallel and jointly shape our bodies and behavior.”

Cultural inheritance, where individuals learn knowledge and techniques from other individuals, has the potential to be much more powerful than genetic inheritance. For instance, a father may teach a boy a particular way of harpoon-making to catch fish. But at age 16, when that same boy is out fishing on the reef and he watches someone else catching way more fish with a different harpoon design, he may copy that design and change his behaviour. Such cultural inheritance results in a much more rapid rate of change than its genetic counterpart, which would require generations of people to have fewer children due to catching fewer fish.

Even in the early 1990s while he was an undergraduate at the University of Sheffield in England, Collard wondered about applying concepts from evolutionary biology to culture. He says, “I was a bit of an oddball in the archaeology department, writing all these wacky essays trying to apply evolutionary theory to things the faculty were surprised to see it applied to.” He went on to Liverpool for a Ph.D. where he used a method called cladistics to study the evolutionary relationships of our fossil relatives. Subsequently at University College London, Collard started applying cladistics to cultural data sets to investigate anthropological and archaeological questions such as the evolution of weaving patterns in Iranian tribal rugs over time. It all culminated with two consecutive £1M five-year grants from the UK’s Arts and Humanities Research Council to form the Centre for Evolutionary Analysis of Cultural Behaviour. The Centre helped put the new evolutionary approach to culture on the map. “Suddenly a whole lot of faculty, postdocs and Ph.D. students were producing papers in which evolutionary methods were applied to cultural datasets, giving talks at conferences, and so on,” says Collard. They changed the field from almost entirely theoretical to one that has a strong empirical component.

Collard became interested in this approach due to a frustration with the hand-waving that characterized work on cultural evolution at the time. There were plenty of theories but little empirical evidence. “My main goal has been to take some of these theories and bring data to bear on them,” he says.

One of the main findings of Collard’s work concerns the importance of vertical transmission in cultural evolution. Vertical transmission refers to the transfer of information from a parent to their child, or from an ancestral population to a descendant population. Since the early part of the 20th century, anthropologists have assumed that vertical transmission is a much less important factor in cultural evolution than horizontal transmission—the transfer of information among peers or contemporaneous populations. However, Collard has demonstrated that the empirical evidence does not support this assumption. His work suggests that vertical transmission often plays an important role in cultural evolution.

Other members of the SFU Centre for Evolutionary Analysis of Cultural Behaviour have discovered that population size plays an important role in cultural evolution. Borrowing from population genetics, they have found a relation between innovation in a culture and population size. It turns out that larger populations are better at maintaining advantageous innovations and cultural information. “When populations shrink there are fewer experts, and as they die, the pool of knowledge and innovations shrinks too, so demographics is a powerful force in cultural evolution,” Collard says. And it’s not linear. Going from 100 to 1000 individuals actually results in more than ten times the innovation. It’s an exponential effect.

The approach that Collard and his colleagues have developed is not without its critics. According to Collard, investigators in the arts and social sciences gravitate toward either a scientific or a humanistic approach in their work. That split is most salient in anthropology where scientists and humanists are often found in same department. “They tend to fight like cats and dogs about how you pursue research and how you evaluate research,” says Collard. “A typical outcome is the total rejection of evolutionary thinking when it comes to human behavior, which is ironic given that anthropology began as the natural history of humankind.” One of Collard’s goals is to put anthropology back together again. “Hopefully, one day we’ll stop treating the cultural and biological aspects of human life differently, and be able to analyze them within a single theoretical framework,” he says. For more information, please visit Collard's website.

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