The triggering of a specific personal memory by another sense, what scientists call autobiographical memory, has always thought to be uniquely human. Descartes’ automata concept, that animals are like biological “machines,” has traditionally also included the concept of a lack of specific memory, and that has been the science community’s party line up until now.
However, studies continue to show that several species of animals possess a much more complex memory than once believed. In her new book, Animal Wise: The Thoughts and Emotions of Our Fellow Creatures, Virginia Morell points out:
The field of animal cognition research has shifted and now embraces the Darwinian approach. Scientists no longer ask, ‘Do animals think?’ Instead, they want to know, ‘How do animals think?’
A recent study at the Leipzig Zoo explored this when it looked to see if chimpanzees and orangutans have autobiographical memories – the ability to explicitly recall past events from a personal perspective.
In 2009, Dr. Gema Martin-Ordas and two others devised a long-term experiment in which eight chimpanzees and four orangutans watched while researchers created a “a constellation of cues: me, the room, and the specific problem” for each individual. Scientists set up the many different cues to later trigger different memories for the individuals, with specific cues designed to trigger the correct tool to use for that particular situation.
Scientists no longer ask, ‘Do animals think?’ Instead, they want to know, ‘How do animals think?’
The scientists conducted various experiments with the chimpanzees and orangutans over three years. And then, in 2012, Dr. Martin-Ordas repeated the experiment with the exact same setup each individual first encountered in 2009.
All but one orangutan used the cues to complete the task the same way they had done in 2009. “I was really surprised that they could remember this event and they did it so fast,” Dr. Martin-Ordas said.
Since researchers used some of the chimpanzees and orangutans in the original 2009 experiment as control subjects, the scientists conducted a second shorter-term experiment in which they again established that the apes could use a single unique cue to remember an event.
Jonathon Crystal, a comparative psychologist at Indiana University, Bloomington, who did not participate in the study, told ScienceNow that the experiments show some nonhuman animals “can remember specific events and retrieve this memory to solve a particular problem…Three years is a remarkably long time to draw on a memory – not just for animals, but for us. It’s breathtaking.”
Although not all scientists are in agreement as to what the experiments prove, they do “move us significantly closer to showing that chimpanzees and orangutans have human-like episodic memory,” Michael Corballis, a cognitive psychologist at the University of Auckland in New Zealand, told ScienceNow.
Whatever may be the final conclusion of these experiments, it is clear that the traditional conceptual model of nonhuman animals as unthinking, unfeeling, automata, with no sense of “self” is outdated and wrong. As experiments continue to show, many nonhuman animals think, feel, emote, love, remember, and live in a remarkably similar fashion to humans. Or, perhaps more accurately, the experiments show that it is in fact humans who think, feel, emote, love, remember, and live in a remarkably similar fashion to our nonhuman animal ancestors.
Note: The Nonhuman Rights Project does not endorse experimentation on captive animals. However, we do quote the results of these experiments when they help make the case that the animals have a level of sentience, self-awareness, and, in some cases, a theory of mind that demonstrates that we should not keep them in captivity in the first place.