Friday, May 19, 2006
According to psychologists in Leipzig, Germany, apes and some birds are able to plan their actions ahead of time.
Psychologists Nicholas Mulcahy and Josep Call at Max Planck Institute for Evolutionary Anthropology say that apes are able to save tools to use at a later time, that will assist them in retrieving food.
The results of the testing are “groundbreaking” and is “a starting point from which we can begin to reconstruct the evolution of the human mind. Apes and jays can also anticipate future needs by remembering past events, contradicting the notion that such cognitive behavior only emerged in hominids,” said Thomas Suddendorf, a psychologist at the University of Queensland Brisbane, Australia.
One aspect of the study is that “our extraordinary abilities of planning for the future did not evolve entirely de novo. Planning for future needs is not uniquely human,” added Suddendorf.
An experiment was performed using bonobos and orangutans. The psychologists placed the apes alone in a room for five minutes. Each of them had a choice of two tools that would allow them to retrieve food and six that would not. The apes were allowed to look at and observe the tools; however, they were not allowed to handle them.
The apes were then taken to a room next door, allowed to take whatever tools they chose, and left alone in the room for at least one hour, while a researcher removed all other tools from the first room. The apes then returned to the first room (where the food was), but the food was not accessible unless they had the right tool to retrieve it.
After repeating the same test several times with each ape, researchers began to see that most apes would begin to use the right tool for the job. Researchers also received similar results even when the apes were left alone in a room overnight where they would sleep.
To make sure that the apes were not associating the tools with the food, they removed the food from the room, but would still give it to the apes if they used the right tool to retrieve it. After this change, most of them did not bring the proper tools, which researchers say confirm that the retrieval is a way of planning for the job.
In experiments using scrub jays (found mostly in the western United States), at the University of Cambridge in the United Kingdom, psychologists have shown that the birds, who usually hide their food to eat later, will hide it again if an enemy bird saw them do it the first time, unless the bird is dominant. The subordinate jay could however, fight the other for the food.
“These results suggest scrub jays remember who observed them make specific caches,” said Joanna Dally who was involved in the study with the scrub jays.
“Together with recent evidence from scrub jays, our results suggest that future planning is not a uniquely human ability, thus contradicting the notion that it emerged in hominids only with the past 2.5 to 1.6 million years,” said Mulcahy and Call in the study.