Baboons Can Think Abstractly

By Cat Lazaroff

WASHINGTON, DC, October 26, 2001 (ENS) - An international team of psychologists has demonstrated that baboons are capable of abstract thought - making them the first non-human, non-ape animal shown to share a central aspect of human intelligence. The findings have profound implications for the evolution of human intelligence and the stuff that separates homo sapiens from other animals.

baboon

Baboons have the capacity for some forms of abstract thought, new research suggests (Photo courtesy tedstrom.com)
The research is significant because baboons are so called old world monkeys, part of a primate family that - some 30 million years ago - split from the family that gave rise to apes and then humans.

Chimpanzees, members of the ape family, have already demonstrated abstract thought. Now, two trained baboons successfully determined that two differently detailed displays were fundamentally the same in their overall design.

Figuring this out required making an analogy - this is to this as that is to that - which many theorists view as the foundation of human reasoning and intelligence.

The study, by JoŽl Fagot, PhD, of the Center for Research in Cognitive Neuroscience in Marseille, France; Edward Wasserman, PhD, of both the Center for Research in Cognitive Neuroscience and the University of Iowa; and Michael Young, PhD, of the University of Iow,a appears in the October issue of the "Journal of Experimental Psychology: Animal Behavior Processes," published by the American Psychological Association.

In a series of five experiments, the researchers trained two adult baboons, one male and one female, to use a personal computer and joystick to view and select grids that had varying collections of little pictures.

sample

One of the sample grids, showing 16 different icons, that would be shown to the baboons first (Photo courtesy American Psychological Association)
In the initial experiment, researchers familiarized the baboons with either a screen display of 16 different little pictures, such as the sun, an arrow, a light bulb, a train and a house, or with a display of the same little picture repeated 16 times - for example, all telephones. Researchers then presented the baboons with a series of choices of two new displays.

In each choice, one display was a 4x4 grid with 16 different icons - for example, a clock, a brain, a hand, a triangle, etc. - the other display was the 4x4 grid with 16 identical icons. Researchers rewarded the baboons for selecting, from two choices, the array that showed the same relationships among pictures as the sample.

Researchers wanted to see whether the baboons could learn to differentiate a subtle and abstract type of "sameness" - linking two grids with two different arrays of 16 different icons, or two grids, each with a different version of 16 identical icons.

The baboons did indeed learn to match the test grids containing 16 different icons to sample grids. They also learned to match the identical icons test grids to sample grids containing repeated images.

It took thousands of trials for them to learn the so called "relation between relations" required by the task, but they did it.

"Although discriminating the relation between relations may not be an intellectual forte of baboons, it is nevertheless within their ken," the researchers said.

The researchers also tested two humans to see their performance compared with the baboons'. The team shrunk the numbers of items in the grid to see whether a lessening in variability (the "different" grids became closer to the "same" grids) affected the baboons' choices.

choices

The baboons were asked to select the grid which was the same as the sample grid - in this example, the top grid would be the correct choice, as it includes 16 different icons - as does the sample above. The lower grid, with one icon repeated 16 times, is the incorrect choice (Photo courtesy American Psychological Association)
Both baboons and humans learned the basic task (although the humans learned far faster), and transferred it to novel sample displays, but humans were far more accurate at matching grids when the number of icons was reduced.

The baboons and humans seemed to have different cutoff points for discerning same versus different, with humans able to make the distinction even when the grids included far fewer icons. The authors speculate that language may play a role, because our verbal expression for "same" makes the idea of "same" more restrictive - in other words, things have to be closer to identical to qualify.

To baboons, the authors suggest, the concept of "same" might be fuzzier and more inclusive.

The baboons' ability to understand abstract concepts opens the door to other species' cognitive potential. The researchers argue that additional research of non-human animals is needed before anyone can conclude that the capability for abstraction is limited only to certain species.

"Analogical thinking and its possible precursors may very well be found in non-human animals - if only we assiduously look for them," the researchers conclude.

The full text of the article is available at: http://www.apa.org/journals/xan/press_releases/october_2001/xan274316.html