Culture–It’s Not Just for Humans Anymore October 24, 2011Posted by Nina Rosenstand in Animal Intelligence, Nina Rosenstand's Posts, Science.
Tags: culture; apes; chimpanzees; orangutans; David Hume; Jane Goodall
What a difference a couple of decades make. Back in the Twentieth Century they used to tell us that humans were the only beings who had culture, and whatever traditions nonhuman animals displayed in their groups could be explained as instinct. That concept began to erode already with Jane Goodall’s research, although we still encounter holdout animal behaviorists who maintain that whatever it is that chimpanzees do when they share and transmit inventions and traditions, it isn’t culture (which brings to mind long-range visionary David Hume who not only thought that emotions have primacy over rationality, but also that if nonhuman animals display emotional and intellectual behavior similar to humans, it should be given similar labels). So what would an example of a chimp culture be like? From a Scientific American blog, “Cultural Transmission in Chimpanzees”:
While nonhuman primates don’t have obvious cultural traditions the same way humans do, such as variation in their clothing or adding extra spice to their food, primatologists have nonetheless identified behavioral practices that vary between communities and which are transmitted through social learning. For a behavior to be considered a cultural practice in nonhuman primates it must meet certain conditions: the behavior must be practiced by multiple members of the community, it must vary between societies, and the potential for that same behavior must exist in other societies.
A good example of such a cultural trait was just discovered last year and published in the journal Current Biology (review here). Kibale Forest chimpanzees were found to use sticks to get at the honey in a fallen log, whereas Budongo Forest chimpanzees used chewed leaves as sponges to collect the same thing. Both societies had the same tools at their disposal, but they each chose a different approach. A single individual first used one of these techniques and other members of the group adopted it through imitation and social learning. This is merely the latest example of cultural traditions in different chimpanzee societies.
So let’s assume that we are convinced that chimps invent and transmit culture; the question now becomes how? In a Swedish study quoted by the Scientific American blog a new idea has been proposed: that culture is being transmitted by female chimps. Chimp societies are patrilocal (the males stay put, the females move between groups), so whatever traditions the females have learned from growing up within a group they will bring with them to their new home, and teach them to their kids:
Because females express and transmit more culture than males, and because females transfer between communities bringing with them their cultural knowledge, the number of cultural traits present in any given chimpanzee community should depend on the number of females in that community. Thus, we hypothesize that the number of cultural traits in chimpanzee communities should correlate with the average number of females in chimpanzee communities, but not with the average number of males.
This implies that females are critical in chimpanzees for transmitting cultural traits and maintaining cultural diversity. The reported pattern may be explained by the fact that females transfer between communities, bringing with them novel cultural traits and consequently increasing the cultural diversity of the community as a whole.
And that’s not all: from a group of Swiss anthropologists we now hear that orangutans also have culture–particularly interesting, because orangutans aren’t perceived (by most of us laypeople) as being as social as chimps:
Researchers from the University of Zurich have now studied whether the geographic variation of behavioral patterns in nine orangutan populations in Sumatra and Borneo can be explained by cultural transmission. They have concluded that it can.
The team analyzed more than 100,000 hours of behavioral data and created genetic profiles of more than 150 wild orangutans. They measured the ecological differences between the habitats of the different populations using satellite imagery and remote sensing techniques.
Co-author of the study, published in Current Biology, Carel van Schaik said: “The novelty of our study is that, thanks to the unprecedented size of our dataset, we were the first to gauge the influence genetics and environmental factors have on the different behavioral patterns among the orangutan populations.”
It seems that the days when researchers would claim that only humans have culture will be over fairly soon. No word on whether orangutan females play the same role as chimp females.