Professor Tetsuro Matsuzawa’s star chimp, Ayumu, was in a 2012 BBC film “Super Smart Animals” because he can remember the sequence and location of nine random digits displayed for only 60 milliseconds. First of all, phone numbers, not including area codes, are seven digits long because that is most people’s short-term memory capacity. More importantly, 60 milliseconds is faster than the blink of an eye.
Some scientists believe we lost this memory capacity during evolution. I disagree because of people like Matt Savage and Kim Peek, savants with extraordinary memories that are effortless. Kim Peek could recite over 12000 books, word-for-word, even backwards. Ordinary people have acquired the savant syndrome and phenomenal memories after accidents or illnesses damaged their cortex, the evolutionarily newest section of our brains. This suggests our ability to remember such detail is not only latent, but utilizes a different mechanism than that requiring an intact cortex. Savants don’t memorize consciously with repetition like most of us. It is as if they record the information, because the retrieval is so effortless. Like the savants, chimps also use their eidetic, or photographic memory, which is much less subject to error than memorization.
One of the first glimpses into chimp cognition was Donald Farrer’s 1967 paper, “Picture memory in the chimpanzee.” Farrer had trained three young chimpanzees to choose the correct picture in each of 24 rows of four pictures. The right answers always matched the pictures located above each row. After the chimps reached 90% accuracy, he presented the same rows of pictures without the answers. To his surprise, the chimps were still 90 to 100 percent accurate. He concluded that they had “memorized” the answers for each of the 24 combinations.
Finding the matching picture is so much easier for humans than using rote memory. And most of us would have quickly learned within a few trials that the correct answer was always just above the row. Why didn’t the chimpanzees? This simple matching task involves a rule, even though it is so obvious that you might not have thought of it as a rule. Chimps can be taught simple rules, but whether they derive them is another matter. We automatically and unconsciously look for these “obvious” rules”, or shortcuts to process information quickly. Young children can tell us “which of these things is like (or not like) the others”… long before they can memorize random number sequences. Even as adults, we struggle with remembering privacy passwords and make errors. But now, with mobile devices in hand, we have achieved our goal of being able to survive without memorizing anything… that is if you are out of school.