James Lee, a psychologist at Harvard University, has announced his research finding that orang-utans are the smartest animals after humans in the world.
How, you might ask, can anyone even begin to compare intelligence among different species when for almost two centuries and thousands of studies on probably millions of people, scientists are still fighting a contentious battle over what intelligence is and how to measure it even in humans. If intelligence is the ability to survive in a particular environment, then intelligence in any absolute sense is immeasurable because skills that can promote survival in one kind of environment can lead to the extinction of an entire species in another.
James skirts the issue by looking at problem solving abilities we recognize as those in which we humans might engage. He asks if there are general characteristics of primate abilities to solve problems, and if so how good the various primates which still survive in the world are at a variety of problems. He has research to support some conventional, and some surprising, conclusions:
- Among primates, the single best indicator of intelligence is brain size. Species with larger brains can, on the whole, solve more problems.
- Primates that are good at solving one kind of problem tend to be good at solving a lot of different kinds of problems.
- The development of brainpower seems to need a certain level of security, which possibly provides time to think. Orang-utans living in food-rich areas with few predators develop a long, settled lives with a unique culture.
- A complex social life in which primates interact with each other and pass on skills to offspring is associated with the development of intelligence.
- Orang-utans can solve more problems even than chimpanzees, and often show a great deal of ingenuity. High in the trees, they can use leaves to make the roofs of their sleeping nests leakproof, teach their young how to make tools and find food, and even make hats for themselves to protect them from the elements.
The ancestors of orang-utans split from the human lineage about 15 million years ago. Today, of all the primates, orang-utans are among the most endangered in the world. The destruction of their forest homes along with hunting and disease are reducing their numbers at an alarming rate.