magazine issue 12 2006 / Issue 1

On Scaffolds and Sweet Potatoes

• written by Arno van Voorst

One of the most simplest things ever made was the scaffold. Thinking about its consequences however has recently opened up a world of possibilities for scientists that might lead to new ways of thinking about culture, the human mind, and their development.

Whenever you take a walk in a large city, you are bound to hear the noise that comes with a growing city. The sound of iron beating on iron, the sight of massive cranes, and the whistling of the workmen when you are a woman and its a hot summer. One of the other structures that is used to build or repair buildings, is the terror of most tourists: a collection of platforms, often made of thick tubes that are frequently completely encasing the building you, as a tourist, wanted to take a picture of. The scaffold however, as such a metal skeleton is called, is really a wonder when you think about it. It is basically a temporary wall that is used to build a structure larger than itself. In addition, such a scaffold can serve as protection when a building is being repaired. Remove the scaffold before the building is finished, and the building will collapse like a house of cards. But once the building is finished, the skeleton is removed and all that is left, is a single beautiful building, which no longer needs any support from any outside source. Often, not a trace is left of the scaffold that aided in the construction of the building.

In science the idea of scaffolds that aid development is quite common. In biology it is assumed that the evolution of certain complex organs was greatly aided by effects of certain genes that originally had a supportive function, but later ended up as obsolete. Thus, the working of such genes would resemble the way a scaffold works. In the research fields that focus on the development of the human mind, the idea of scaffolds is slowly appearing as well, supported by the ideas of the philosopher Vygotsky. This Vygotsky observed that young children often repeated to themselves what they should do when doing difficult tasks. He concluded that language could act as a scaffold for children, serving as an aid during complex tasks and guiding their behaviour and concentration.

Others went even further, and suggest that our present level of thinking is only possible due to the supportive functions of language. The idea of scaffolds could however also be used to explain cultural changes. The invention of a tool of sorts could lead to changes in people’s life styles and even change the way we think about the world. An example of this would be the clock, a device that inspired the philosopher Descartes into thinking that animals are nothing but complex clocks or robots, and human bodies were no exception. Although Descartes gave humans the added extras of a spirit that resides in the brain and makes us fully human – an idea that remains hotly disputed by philosophers, psychologists and animal rights activists – it is clear that the idea of the body as a machine has been with us ever since.

The problem with all these ideas however, is that they are just that: ideas. Often it is hard to test whether something is really a scaffold, or that scaffolds even exist. If they did, they could greatly enhance scientific theories about biology, psychology, philosophy and sociology. All in all would proof of how small changes in behaviour can lead to stable, self-sustaining collections of behaviours be a serious help.

Interesting enough, such a proof is actually already available, but often gruesomely overlooked. This evidence on scaffolding comes from the rise of a cultural habit among an unlikely group: the Japanese macaques on the small island of Koshima. The research done there is often mentioned by scientists as an example of culture among animals, though usually these same scientists only focus on the first small discovery. As the story is so amusing, yet fascinating when one looks at the bigger picture, I will give a full account here.

Monkey business

Starting in 1952, a group of Japanese researchers led by Masao Kawai started to observe the macaques of Koshima. They had a minor problem though: the macaques preferred to stay in the woods, which didn’t make observing them any easier. So, at some point the researchers decided to lure the macaques to the more open beaches. This was done with the aid of sweet potatoes, which they scattered around the beach to attract the hungry monkeys with.

The monkeys came, and indeed ate the potatoes. Unfortunately did the new food come with the problem of sand between the monkeys teeth. As most parents know when they put their small child in the sand box with some sweets, do sweets often end up covered with sand, with the children crying because their candy suddenly has a dirt flavour. Macaques show more initiative than small children though and started to clean their potatoes by rubbing it back and forth between their hands. Still, it remained a poor solution for getting rid of the sand.

Some years later however, a young female named Imo suddenly had an idea. Instead of rubbing the sand from the potatoes, she walked up to a nearby stream and started to wash her potatoes. This simple act became the macaque version of the discovery of fire. Many of her group watched her, and started to wash their potatoes as well. With this, an appearance of the potato washing macaques was a fact.

This is a relatively well-known story, backed up by scientific evidence and observations for over 50 years. It is therefore a shame that only this single habit is highlighted, as much more has been discovered …by the macaques, that is.