Holding a mirror up to a gibbon’s mind

March 4, 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: Shouldering the burden of evolution

Related Stories

Shouldering the burden of evolution

September 8, 2015

As early humans increasingly left forests and utilized tools, they took an evolutionary step away from apes. But what this last common ancestor with apes looked like has remained unclear. A new study led by researchers at ...

Apes may be closer to speaking than many scientists think

August 14, 2015

Koko the gorilla is best known for a lifelong study to teach her a silent form of communication, American Sign Language. But some of the simple sounds she has learned may change the perception that humans are the only primates ...

A model for ageing

August 7, 2015

Life is short, especially for the killifish, Nothobranchius furzeri: It lives for only a few months and then its time is up. During that short lifespan it passes through every phase of life from larva to venerable old fish. ...

Making sense of our evolution

July 13, 2015

The science about our our special senses - vision, smell, hearing and taste - offers fascinating and unique perspectives on our evolution.

Recommended for you

Trade in invasive plants is blossoming

October 3, 2015

Every day, hundreds of different plant species—many of them listed as invasive—are traded online worldwide on auction platforms. This exacerbates the problem of uncontrollable biological invasions.

Ancestral background can be determined by fingerprints

September 28, 2015

A proof-of-concept study finds that it is possible to identify an individual's ancestral background based on his or her fingerprint characteristics – a discovery with significant applications for law enforcement and anthropological ...


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.