What is the average IQ of an ape?

Answer 1

IQ tests must be closely matched to the culture and environment of the subject. It is impossible to devise an accurate IQ test for non-human species, since we are unable to construct tests that take their internal viewpoint into account. Any such numbers that you read are only estimates, based on human-centered expectations.

Most estimates of intellectual capability put apes and chimps at about the level of about a 2-year-old human child. On the other hand, they can survive in the jungle. If we gave a child a test based on jungle survival, it would fail dismally -- unless it were raised in the jungle and understood it. You can see the difficulty of testing subjects that are not in their natural habitat, and incarcerated to boot.