A study on chimpanzee intelligence by researchers from the Yerkes National Primate Research Center in Atlanta found out half of chimp intelligence is due to genes and the other half is due to environmental factors.
William Hopkins, lead author of the study and a primatologist from the Yerkes National Primate Research Center, and his colleagues studied the mental capabilities of 99 chimpanzees in captivity. They designed a series of 13 tests to measure the chimps’ ability to deal with their physical environment, intelligence, and reaction to stimuli by using simple tools.
The chimps all were part of the same big family tree; with some being full siblings and others have fourth and fifth cousins. This large genetic map gave researchers data to calculate how genes manifest in a particular chimp family.
They discovered that there were two types of tasks that could be passed on through genes: one was spatial cognition, a capability that enables humans to manage easy and challenging cognitive tasks in daily life; and dealing with the physical environment. The researchers saw some chimps making kissing sounds and others clapping their hands to get attention.
“This one is a real measure of intelligence and innovative behavior,” Hopkins said to the National Geographic.
Findings of the study support the social brain hypothesis, a theory in which human intelligence was a by-product of our evolution that helped our ancestors survive and prolong relationships in a large and social group.
Though the focus of the study was the effects of genes in chimpanzee intelligence, Hopkins and his team were also able to observe some strong environmental cues that may affect their intelligence.
Additional details of this study were published in the July 10 issue of Current Biology.
Study: Chimpanzee Intelligence is Based On Genes and Environmental Factors