A recent study on chimpanzee intelligence done by researchers from the Yerkes National Primate Research Center in Atlanta revealed that half of chimp intelligence is due to genes and the other half is due to environmental factors.
“Chimps offer a really simple way of thinking about how genes might influence intelligence without, in essence, the baggage of these other mechanisms that are confounded with genes in research on human intelligence,” Dr. William Hopkins, professor in the Center for Behavioral Neuroscience at Georgia State, said.
Chimpanzees don’t just get their smarts by aping others — chimps, like humans, have their genes play a really important role in their performance on tasks while non-genetic factors didn’t seem to explain a lot.
American psychologists John Watson and B.F. Skinner developed the notion of behaviorism in the early 20th century. The notion suggested that scientists are supposed to go through only the behavior of animals, not their mental processes. This was the dominant approach until about 1985.
The study involved 99 chimpanzees, ranging in age from 9 to 54, who completed 13 cognitive tasks designed to test a variety of abilities. The chimps belonged to a big family tree, with some being full siblings and some having fourth to fifth cousins.
There were two types of tasks that they discovered could be passed on through the genes; one was spatial cognition, which makes humans able to manage easy and challenging cognitive tasks in daily life; and dealing with the physical environment. The researchers observed some chimps making kissing sounds and clapping their hands for attention.
“This one is a real measure of intelligence and innovative behavior,” Hopkins said.
“We have what we would call a smart chimp, and chimps we’d call not so smart,” Hopkins told, and “we were able to explain a lot of that variability by who was related to each other.”
“The fact that we can establish this in an organism that has none of the baggage of our social-cultural systems points strongly to the role that genes play in their intelligence,” he said.
The results suggest that “nature” matters a bit more than “nurture” for intelligence.
The findings are reported in the latest issue of Current Biology.