Chimps & Orangutans Recalls their past

Scientists now found that chimpanzees and orangutans can apparently remember things which are, happened years ago in their lives, just like humans.

The skill to remember events from the distant past has been considered as a defining feature of human nature, said by a comparative psychologist Gema Martin-Ordas, of Aarhus University in Denmark. At the present she and her colleagues find that chimpanzees and orangutans can also remember distant memories. These consequences show that we have more in common than we formerly thought with our closest relatives  

A Experiment on  15 chimpanzees and four orangutans was conducted, the scientists tested whether the animals could memorize events they experienced years ago or not. Three years previous, the apes had watched the researchers to hide the tools that the chimpanzees and orangutans needed to grab rewards, which were otherwise out of their reach. As the researchers repeated hiding the tools a total of four times, the apes looked on.

In the new experiment, the scientists made the apes carry out the same tasks, in the same quarters, with the same experimenters. With just one exemption, all the apes had to recall where the necessary tool was hidden to reach its reward.

 It was surprising to know that they not only remembered the event that took place three years ago, but also the did it fast. On average it took five seconds to go and find the tools.

The short amount of time suggests the animals did not simply walk around until they found the tools rather than they recalled the event that enabled them to find the tools directly.

The researchers had repeat the experiment on chimpanzees and orangutans one more time by taking another tool-finding task, with a slightly different arrangement, and then made them to repeat it two weeks later. Similar results were seen — the animals immediately remembered where to look — even though the apes initially carried out the task only once.

These findings also proved that the chimpanzees and orangutans could differentiate between similar past events in which the same locations and people were involved.

"This is the first study showing that chimpanzees and orangutans remember personal past events that took place a long time ago, when presented with the appropriate cues," Martin-Ordas said. "I think these two studies open up a completely new line of research to approach the study of memories for past events in nonhuman animals."

The scientists detailed their findings July 18 in the journal Current Biology.