London, April 19 (ANI): Just like humans, apes are sufficiently self-aware to doubt their own knowledge, says a new study.
As part of the research, Josep Call of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, put food in one of two opaque plastic pipes and had watching bonobos, chimpanzees, gorillas and orangutans pick the one with the food.
Call found that if they were made to wait, the apes sometimes forgot where the food was, but by and large they did well on the task, reports New Scientist.
To find out if the apes doubted their own decisions, Call gave them the option to peek into the end of the pipes before they chose one.
He found that the apes were more likely to check the pipes if they had to wait before picking one.
Call says this suggests that the apes had begun to doubt their memory.
The study has been published in the journal Animal Cognition. (ANI)