Science + Technology

Monkeys Learn in the Same Way as Humans, Psychologists Report


Monkeys seem to learn the same way humans do, a new researchstudy indicates.

"Like humans, monkeys benefit enormously from being activelyinvolved in learning instead of having information presented to them passively,"said Nate Kornell, a UCLA postdoctoral scholar in psychology and lead author ofthe study, which appears in the August issue of the journal PsychologicalScience. "The advantage of active learning appears to be a fundamental propertyof memory in humans and nonhumans alike."

In Kornell's study, conducted when he was a psychologygraduate student at Columbia University, two rhesusmacaque monkeys learned to place five photographs in a particular order. Thephotographs were displayed on a touch-screen computer monitor similar to thosefound on ATMs. When the monkeys pressed a correct photograph, a border appearedaround it. When either monkey pressed all five photographs in the correctorder, he received a food reward. The chance of guessing all five accurately isless than one percent.

In all, each monkey learned to order at least 18 separateseries of photographs, which included such items as a fish, a human face, abuilding, a football field and a flame from a match. They underwent three days oftraining before being tested.

In some of the training trials, the monkeys had to figure out the correctorder themselves, while in others, they had the option of getting help bypushing an icon in the corner of the screen that caused the border of thecorrect photograph to flash. They were rewarded with an M&M candy each timethey correctly completed the task without help and with a less desirable foodpellet when they completed the task with hints from the help icon. After threedays, the monkeys were tested without the benefit of the help icon.

"Both monkeys did much better if they had studied without ahint than if they had studied with a hint," Kornell said. "The monkeys did muchbetter on the first three days when they had the help than when they didn't,but on the test day, it completely reversed. When they studied with the hint,there is no evidence they learned anything about the list. They learned thelists when they didn't get the help."

The findings are closely related to findings in humans thatrecalling answers from memory enhances long-term learning.

"The findings were somewhat unintuitive, because passivelyusing the hint appeared to enhance performance during the study phase of theexperiment but had a deleterious effect on long-term learning," Kornell said.

What are the implications for human learning?

"Many people incorrectly assume the better you do as you'restudying, the more you're learning," said Kornell, who works in the laboratoryof Robert A. Bjork, professor and chair of psychology at UCLA. "If studentsdon't test themselves when they read a chapter, they can easily think they knowthe material when they don't. When you test yourself as you study, you may feellike you're making it harder on yourself, but on the test, you will do muchbetter. Robert Bjork calls this 'desirable difficulty.' If you want to learnsomething well, when you're reading, stop and think about what you've read, andtest yourself; you learn by testing yourself. If you make it more difficult foryourself while you study, you feel like you're doing worse, but you're learningmore.

"Active learning is important in humans and — this studydemonstrates — in monkeys as well," he added.

Less effective passive learning includes listening to apresentation and reading without testing yourself or summarizing what you havelearned.

"When you summarize the material in your own words, that'smuch more active," Kornell said. "You can't do that if you don't understandit."

Cramming right before a test does not work as well asspacing studying out over a longer period of time, Kornell added, citing otherresearch on learning and memory.

Kornell's research, supported by the National Institute ofMental Health, was conducted with Herbert Terrace, a professor of psychology atColumbia. Thetwo monkeys, Macduff and Oberon, are housed at the New York State PsychiatricInstitute, where Terrace has a joint appointment. Neither animal was harmed inthe study, and they were fed daily regardless of how they performed in thetrials.

"Many people," Kornell noted, "have had the experience oflistening to a computer instructor open a menu and go through a series ofsteps. Then you try to do it, and you don't even know which menu or what thefirst step is. If you are passively following along, you won't remember it aswell as if you're forced to do it yourself. Active learning is much harder, butif you can do it successfully, you will remember it much better in the longrun.

"If you're learning to serve a tennis ball, you won't getmuch out of an instructor taking your arm and practicing the swing over andover," he said. "That's not going to help you nearly as much as if you servethe ball yourself."

The situation is the same for monkeys, according to Kornell.

"The way the monkeys learn to remember the correct answersis through active learning, like humans," he said. "They have to generate theanswers themselves from memory. Generating the correct sequence from memoryresulted in more long-term learning than the more passive training with hints."

Kornell noted that more than a century ago, author WilliamJames remarked on the importance of being actively involved in learning. Sincethen, science has proven him correct. Kornell also noted that his research confirmsthe teachings of another monkey: Curious George.

UCLA is California's largestuniversity, with an enrollment of nearly 37,000 undergraduate and graduatestudents. The UCLA College of Letters and Science and the university's 11professional schools feature renowned faculty and offer more than 300 degreeprograms and majors. UCLA is a national and international leader in the breadthand quality of its academic, research, health care, cultural, continuingeducation and athletic programs. Four alumni and five faculty have been awardedthe Nobel Prize.



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