Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Apes -- not monkeys -- ace IQ tests

02.08.2006
The great apes are the smartest of all nonhuman primates, with orangutans and chimpanzees consistently besting monkeys and lemurs on a variety of intelligence tests, Duke University Medical Center researchers have found.

"It's clear that some species can and do develop enhanced abilities for solving particular problems," said Robert O. Deaner, Ph.D., who led the study as part of his doctoral dissertation. "But our results imply that natural selection may favor a general type of intelligence in some circumstances. We suspect that this was crucial in human evolution."

The study was published online August 1, 2006, in the journal Evolutionary Psychology. Funding was provided by the medical center's Department of Biological Anthropology and Anatomy.

Experts in psychology broadly define intelligence as general problem-solving skills -- "domain-general cognition" in the parlance of the field. This intelligence allows an animal to tackle new and unpredictable situations. Domain-general cognitive ability is separate from domain-specific abilities for solving certain environmental challenges, such as a bird remembering where it cached food.

Intelligence testing of animals has repeatedly revealed that some species perform better than others. This suggests that some animals have better domain-general skills, Deaner said. However, scientists have been hard-pressed to convincingly prove these differences could be attributed to intelligence, he added.

"The trouble is that one species may outperform another in a problem-solving test not because it's smarter, but because one species is poorly suited to that particular testing situation," he said. For example, one species may be more comfortable grabbing a joystick.

Deaner and his colleagues reasoned that they could refute this premise -- that performance differences resulted from particular testing situations -- by demonstrating that some primate species surpassed others across a wide range of problem-solving tests. Primates are an excellent comparison group because their similar perceptual and motor skills means that the same tests are generally appropriate for all of them, Deaner said. But developing a suitable data set to test this idea was not easy.

"At first we thought gathering the data would require a lifetime," said Deaner, now an assistant professor of psychology at Grand Valley State University in Allendale, Mich. "Ideally, one would test several individuals from each of 20 or 30 species with dozens of cognitive tests, but this certainly didn't seem practical. Then we realized the data had already been gathered by an army of comparative psychologists."

The team first pored through hundreds of published studies, then assigned each testing situation or experiment to one of nine overall paradigms. For example, one paradigm was patterned strings. During the test, a primate is shown an array of crossing strings, only one of which is tethered to a treat. The subject is allowed to pull only one of the strings and must decide before pulling which string is actually attached to the food. The paradigm taps the ability to form spatial representations, considered crucial for intelligent behavior.

The results were clear: there were a few cases where one species performed better than another one in one task and reversed places in a different task, but, overall, some species truly outperformed others. "Our research strengthens the long-standing notion that some animal species truly are more intelligent than others," Deaner said. The smartest species were clearly the great apes -- orangutans, chimpanzees, and gorillas – which performed much better than monkeys and prosimians.

"The fact that great apes performed better than other primates in these laboratory tasks is reassuring," said Carel van Schaik, Ph.D., a study co-author and director of the Anthropological Institute and Museum at the University of Zurich. "After all, in absolute terms, their brains are the largest and they show the most sophisticated behavior under natural conditions -- deception and culturally-transmitted behavior, including tool-use."

Though some species clearly outperformed others, there was no evidence that any species performed especially well within a particular paradigm. This result contradicts the theory that species differences in intelligence only exist for narrow, specialized skills, Deaner said. Instead, the results argue that some species possess a broad, domain-general type of intelligence that allows them to succeed in a variety of situations.

Team statistician Valen Johnson, Ph.D., a professor of biostatistics at the University of Texas M. D. Anderson Cancer Center, created a new statistical technique to examine the data for consistency across the various tests. "It was tougher than it looks, because most species were only tested in a few situations," Johnson said. "Conventional methods wouldn't do the job."

Robert Deaner | EurekAlert!
Further information:
http://www.dukemednews.org

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>