by Michelle Y. Merrill, Ph.D.
At first glance, orangutans seem inappropriate mentors for learning about organizations. Most monkeys and apes form groups with social mechanisms for maintaining group bonds and minimizing conflict. In contrast, orangutans spend most of their adult life apart from other mature orangutans. Yet orangutans, like the more social chimpanzees, were recently found to possess some simple forms of behaviors once believed unique to humans: widespread tool-use and cultural variation.
Anthropologists often study orangutans, chimpanzees and other closely-related primate species as a way to better understand the evolution of the human lineage. Technology, even the simplest tool use, generally requires complex, learned behavior. Cultural variation occurs when social learning leads to differences in behavior between populations. In 1999 I went to Sumatra to study orangutan social behavior, with an eye to investigating how culture and technology evolved.
I was comparing orangutan populations at two rainforest sites: Ketambe, in the hills, and Suaq Balimbing, in the lowlands. While some simple tools were used at both sites (for example, using leafy branches like an umbrella to shelter from the rain), only the orangutans at Suaq Balimbing were frequently using tools for extractive foraging (usually poking a stick into a hard-to-reach place to pull out something good to eat, like getting honey from a bees’ nest in a hole in a tree).
Another difference between the sites was how gregarious the orangutans were.
The population densities were similar at both sites, and orangutans at both sites spent similar amounts of time within 50 meters of their nearest neighbor. But at Suaq Balimbing, adult orangutans spent more time in very close proximity (less than 10 meters from one another) compared to the orangutans at Ketambe. They also had a larger network of apparent “friends,” different orangutans with whom they were willing to remain in close proximity.
Could these differences in technological complexity and social tolerance be related? I think they are, in a simple feedback interaction. Here’s how it works:
- Orangutans that spend more time close together have more opportunities to learn new behaviors from their peers (more social tolerance gives more time to learn from others).
- Orangutans with larger social networks have opportunities to learn from diverse models, thereby potentially adding more innovations and variations to their behavioral repertoire (diverse associates lead to behavioral diversity and flexibility for individuals).
- A growing repertoire of skills makes new resources available to the orangutans, reducing the need to compete and fostering even greater social tolerance in an environment of abundance (more behavioral diversity and flexibility can lead to more social tolerance).
This feedback cycle may be best illustrated by the Neesia fruit that some orangutans use. The Neesia is a large fruit with a woody outer husk, sort of like a coconut and just as big. When the seeds inside are ripe, seams open up along the sides of the fruit. The seeds are a real treat, with a wonderful taste like sweetened cashews and coconut milk. They provide a compact package of proteins and fats that orangutans crave to supplement their usual diet of fruits and leaves. These nutritious seeds would be especially beneficial to female orangutans while they are pregnant or nursing (and they are almost always one or the other).
An orangutan could probably poke a finger in to get the seeds, but it would be exceedingly unpleasant because the inside of the Neesia fruit is lined with little spine-like hairs that get into the skin and itch. Huge male orangutans can break open ripe Neesia fruits to pick out the seeds without getting stung by the hairs. But these males can be twice the size of adult female orangutans. The Neesia fruits are too tough for smaller orangutans to open with this brute-strength approach, so in most places female orangutans almost never get to eat any. At Suaq Balimbing, the orangutans use technology to solve this problem, modifying twigs so they can be inserted to pry out the Neesia fruit’s rich seeds. When the Neesia fruits are open at Suaq Balimbing, it is not uncommon to see several females feeding on them in the same tree, with very little conflict over sharing this abundant resource.
A subadult male uses a Neesia tool, while an adolescent female watches.
The example of positive feedback in the development of orangutan technology is probably a good model for how humans first came to rely on tool-use, and what made us so successful as a species that we are now affecting (some would say threatening) the entire biosphere. But this model can also inform how we look at learning organizations today. For best practices to spread and be maintained throughout an organizational culture, there must be sufficient close contact and social tolerance for observational learning, with social networks spanning many individuals, in a way that reduces inter-individual competition. Even the antisocial orangutans can teach us that.
What other organisms might we look to for even more information about how to function in social networks and organizations?
In addition to my own dissertation research, these ideas are based on some work that I did with my colleagues, published in:
van Schaik , C. P., M. Ancrenaz, G. Borgen, B. Galdikas, C.D. Knott, I. Singleton, A. Suzuki, S. Utami, M. Merrill. 2003. Orangutan cultures and the evolution of material culture. Science 299(1): 102-105.
van Schaik, C.P., Deaner, R.O., Merrill, M.Y. 1999. The conditions for tool use in primates: implications for the evolution of material culture. Journal of Human Evolution 36(6): 719-741.
I originally posted this article at emergentsystems.com, circa 2005.