Holding a mirror up to a gibbon’s mind

Mar 04, 2009
Holding a mirror up to a gibbon’s mind

(PhysOrg.com) -- University of Queensland developmental psychologists have taken a step into our evolutionary past by studying gibbons.

Associate Professor Thomas Suddendorf and Dr Emma Collier-Barker, from UQ's School of Psychology, studied gibbons from several zoos in Australia as well as at the Smithsonian Institute in Washington to see if they were capable of recognising themselves in mirrors.

“We know that human children develop this ability before they turn two, and we know that great apes - chimpanzees, gorillas and orangutans - can do this as well,” Dr Suddendorf said.

“Our research shows that lesser apes, such as gibbons and siamangs, do not have this ability.”

Dr Suddendorf said the research added a crucial piece to an evolutionary puzzle.

“The fact that humans and our closest living relatives, the great apes, can pass the task suggests that this capacity was inherited from a common ancestor,” he said.

“The last common ancestor of all great apes lived about 14 million years ago. Gibbons split from our evolutionary tree about 18 million years ago. The current results therefore suggest that the trait evolved between 14 and 18 million years ago.”

He said the findings also informed the search for the neurological and genetic underpinnings of the capacity to self-recognise.

“We can now ask what self-recognizing great apes and humans have in common that they do not share with non-self-recognizing lesser apes,” he said.

The research involved exposing gibbons to mirrors and then surreptitiously placing paint on their forehead.

“None of the apes recognized that the mark they could see in the mirror was on their own head. Instead, most of them looked or reached behind the mirror as if looking for another gibbon,” he said.

Various control conditions showed the apes were motivated to find marks. In one of these, the researchers used cake icing and found that the gibbons scraped icing from their legs and even from the mirror surface itself, but continued to ignore the icing on their own face that they could see in the mirror.

“It is difficult to establish the absence of a capacity, but the current results strongly suggest that the lesser apes just do not get it.

“What's kind of cool about these results is that, together with the data from great apes, they create a comparative picture that allows us to reason about the minds of our extinct great ape ancestor, even without laying eyes on any fossils.”

The research, funded by an ARC Discovery Grant and a Queensland-Smithsonian Fellowship, was recently published in the journal Proceedings of The Royal Society B.

More information: rspb.royalsocietypublishing.org/

Provided by University of Queensland

Explore further: Aging white lion euthanized at Ohio zoo

add to favorites email to friend print save as pdf

Related Stories

Great apes facing 'direct threat' from palm oil farming

Nov 20, 2014

The destruction of rainforests in Southeast Asia and increasingly in Africa to make way for palm oil cultivation is a "direct threat" to the survival of great apes such as the orangutan, environmentalists ...

Researcher uses genes to map evolution of species

Sep 12, 2014

Genes, whether from apes or the trees they live in, are the storytellers of the origins of a species, according to a Texas A&M University ecosystem science and management assistant professor in College Station.

Non-dominant hand vital to the evolution of the thumb

Sep 10, 2014

New research from biological anthropologists at the University of Kent has shown that the use of the non-dominant hand was likely to have played a vital role in the evolution of modern human hand morphology.

Wildlife 'WikiLeaks' targets Africa poaching elite

Aug 25, 2014

Poachers slaughtering Africa's elephants and rhinos with impunity are often shielded from police by powerful connections, but a group of conservationists has turned to the anonymity of tip-offs to try to ...

Recommended for you

A vegetarian carnivorous plant

Dec 19, 2014

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.