Skip to content

Intelligence Among Humans and Other Animals

By Russell Tenofsky

Scientific thought is evolving to recognize that the difference between human and nonhuman animal intelligence is not as wide as once thought. This shift in ideology is gaining momentum, and scientists are beginning to erase their historically held anthropocentric prejudices about the meaning of intelligence.

Photo of a herd of elephants near a water source, featuring front-and-center two calves.

Primatologist Frans de Waal, Professor at Emory University and director of the Living Links Center at the Yerkes National Primate Research Center, is well-known among the scientists who are starting to recognize that the traditional measurements of nonhuman animal intelligence are no longer valid.

De Waal is the author of The Bonobo and the Atheist, where he argues that morality does not come from an outside source, but is rather the product of evolution. He writes about this in a column in the Wall Street Journal.

“A growing body of evidence shows that we have grossly underestimated both the scope and the scale of animal intelligence. Do chimpanzees have a sense of fairness? Can birds guess what others know? … Just a few decades ago we would have answered ‘no’ to all such questions. Now we’re not so sure.”

This change in thought is naturally accompanied by a completely revamped way in which scientists conduct experiments and interpret data.

“Experiments with animals have long been handicapped by our anthropocentric attitude: we often test them in ways that work fine with humans but not so well with other species. Scientists are now finally meeting animals on their own terms instead of treating them like furry (or feathery) humans, and this shift is fundamentally reshaping our understanding.”

We are now re-examining experiments involving a wide-range of species, resulting in a much-needed overhaul of the way we view the research “subjects” themselves. Included in this re-evaluation is what de Waal calls “negative evidence” – evidence that was always there but that scientists overlooked because of its apparent absence.

De Waal compares this to not seeing or hearing a woodpecker while walking through the woods. Not seeing or hearing the woodpecker does not prove that the bird does not exist but that you are just not experiencing the bird at that time. Scientists have historically taken this view when studying nonhuman animal intelligence.

“Underlying many of our mistaken beliefs about animal intelligence is the problem of negative evidence. It is quite puzzling … why the field of animal cognition has such a long history of claims about the absence of capacities based on just a few strolls through the forest.”

Constructing new experiments and recognizing different species’ viewpoints denotes the much-needed leap forward in scientific thought. Scientists are beginning to recognize nonhuman animal intelligence as separate and unique from humans but still no less valuable. Hopefully, for the sake of nonhuman animals, scientists will continue to stroll on through this forest.

Note: The Nonhuman Rights Project does not endorse experimentation on captive animals. However, we do quote the results of these experiments when they help make the case that the animals have a level of sentience, self-awareness, and, in some cases, a theory of mind that demonstrates that we should not keep them in captivity in the first place.

Sign up to receive the latest updates on our mission

Find out about opportunities to get involved, breaking news in our cases and campaigns, and more.