An article written by Professor Andrew Whiten FBA, Professor Robert Hinde FBA FRS, Professor Chris Stringer FRS and Professor Kevin Laland.
Culture, broadly defined as all we learn from others that endures for long enough to generate customs and traditions, shapes vast swathes of our lives and has allowed the human species to dominate the planet. Indeed, our ‘capacity for culture’ appears so distinctive among animals it is often thought to separate we cultural beings from the rest of nature, and the Darwinian forces that shape it.
Professor Andy Whiten discusses the idea of cultural evolution. (1:30 mins, requires Flash Player).
However, a contrary conclusion has arisen in the recent discoveries of a hitherto disparate range of scientific disciplines.
The ‘discontinuity’ view of human culture has been challenged in two ways. One is that the roots of social learning, tradition and culture are increasingly being traced in a widening array of non-human species. The other is that the ways in which culture itself evolves are being elucidated, extending and enriching our understanding of the Darwinian and other processes that shape the biosphere and our place in it. Culture, long the almost exclusive province of social scientists, has become a topic increasingly tackled by scientific methodologies, from sophisticated numerical and modelling techniques to field and laboratory experiments.
Professor Armand Leroi on the biological perspective on the evolution of culture (2 mins).
- Listen here.
Accumulating data representing decades of study of a number of mammals including dolphins, meerkats, monkeys and apes, have charted the existence of sometimes dozens of putative local traditions at different field sites. In chimpanzees and orangutans these encompass behaviour patterns including foraging techniques, tool use, courtship ploys and social customs that suggest ancient origins for the capacity to sustain complex, multi-tradition cultures once thought unique to humans. These long-term observations have recently been strengthened by experimental studies demonstrating the spread and maintenance of seeded artificial foraging techniques in both captive and wild mammals, from mongooses to chimpanzees.
An adult meerkat holds down a cricket that it has brought for a pup (credit: Alex Thornton).
More generally, social learning has been shown to be widespread in the animal kingdom, extending to insects and other invertebrates. Some of the most robust evidence for traditions is now available in birds, where the relative ease of cross-fostering through egg transfer has demonstrated the role of learning from parents, and in fish, where a variety of experimental manipulations has established phenomena like the power of social learning to maintain travel route traditions. An ‘ecology of culture’ is also emerging. For example, teaching-like behaviour is now recorded among diverse predatory species where young need to make the difficult leap from incompetence to competent prey-capture, yet is minimal at best in our closest primate relatives, where a largely vegetarian diet can be more gradually acquired even when it requires skilled tool use.
Dr Christine Caldwell on social learning among meerkats (3 mins).
- Listen here.
New discoveries have pushed the roots of humanity’s capacity for cumulative culture into ever more ancient timeframes. The record of stone tool manufacture now extends back to 2.6 million years. A similar trend now emerges in relation to the classical view of a cultural ‘revolution’ 30-40 thousand years ago, with evidence for such aesthetic achievements as cave paintings. An exciting range of new evidence has revealed more ancient origins of this aspect of human culture, including shell beads and large quantities of ochre, dating back at least 100,000 years in Africa.
The subsequent spread and diversification of culture have been investigated using tools developed to study biological evolution. Language evolution has proved a particularly productive topic for the application of these numerical approaches to constructing (cultural) phylogenetic trees. A remarkable parallel has been demonstrated between the picture of language evolution coupled to the peopling of the Pacific islands and independent evidence on the latter derived from the distribution of the gut bacteria Heliobacter pylori. These kinds of phylogenetic analyses are being increasingly extended to other domains of culture, from technologies to political structures.
Chimpanzee culture (credit: Professor Andrew Whiten).
How evolution had shaped mental ontogenetic processes to facilitate the assimilation of culture adds developmental psychology to the eclectic mix of ethology, psychology, archaeology, anthropology and other disciplines brought together in the current discussion in this field. Given how well we might assume we know the young of our species, it is remarkable that revolutions in our understanding are emerging. Ingenious new experimental approaches have revealed what appears to be an intriguing cognitive mosaic, encompassing both sophisticated rules guiding optimal learning from others in infancy, alongside striking tendencies for conformity and ‘over-imitation’ so powerful they can lead children into radical, although recoverable, lapses into false beliefs.
Bringing together a wide range of perspectives on cultural evolution is a productive step forward in building a modern science of culture. Cultural transmission has been shown to be a much more widespread phenomenon in the animal kingdom than could have been suspected a few decades ago, and as a ‘second inheritance system’ accordingly has important implications for evolutionary biology generally, extending to gene-culture co-evolution. It has been shaping the course of human evolution for longer and in deeper ways than hitherto thought; and excitingly, it is proving amenable to rigorous, but imaginative, systematic scientific investigations, generating real progress in our understanding of how “culture evolves”.
Banner image: Flints from a paper by Joseph Prestwich, 1860. From the Royal Society archive.