Chimps Like Movies Starring People in Ape Suits
Chimps seem to enjoy -- and remember -- a good thriller, especially when at least one of its stars is dressed like an ape.
Chimps and bonobos become very engrossed in movies featuring characters dressed in ape suits, found a new study that also tested the furry viewers' memory skills.
The primates aced the tests, remembering and anticipating the memorable events that they saw on screen, even if they watched the film just one time. The study's findings are published in the latest issue of the journal Current Biology.
Prior research appears to support the findings, as evidenced by the following footage of Koko the gorilla watching one of her favorite movies, "Tea with Mussolini." When it comes to a sad part, where a boy in the film has to say goodbye to all of his relatives and waves adios on the train, Koko turns away from the TV. She then proceeds to sign: "Frown, sad, cry, bad, trouble, mother and Koko-love." Her eyes, according to her caretakers, also tear up. (Gorillas are known to cry during emotional moments.)
"When you watch a shocking, emotional event in a movie, you remember the event well, and later on, when you watch the same movie, you anticipate the event," co-author Fumihiro Kano of Kyoto University said in a press release.
"Thanks to a recent advance of state-of-the-art eye-tracking technologies," he added, "we could examine event anticipation by great apes while watching a movie by means of ‘anticipatory looks' to the impending events."
To do this, Kano and his team created two short films starring themselves. In the first flick, an aggressive person in an ape suit comes out from one of two identical doors. In the second film, a human actor grabs one of two objects and attacks the ape-like character with it.
Both films were shown to six chimps and six bonobos, who were riveted to the screen, so much so that they did not want any distractions, however tasty.
"We were giving juice while showing the videos to them," Kano explained, "but some of them even forgot to drink juice and stared at the movies!"
An eye tracker, which monitored all of the eye movements of the chimps and bonobos as they watched the films, showed that the primates anticipated what they were about to see after a single viewing of the movie.
On a second viewing of the first movie, the primates directed their attention to the door where they knew the person dressed as an ape would appear. While watching the second film again, the animals looked in anticipation at the object they knew would soon be used as a kind of weapon, even when that object was placed in a different location than they had seen earlier.
All of this means that the chimps and bonobos stored information from the first film into their long-term memories, just as humans do. They were then able to use that info later to anticipate events that were about to happen.
Aside from the novelty of the findings, the research is enabling the scientists to determine what high-level cognitive functions non-human primates are capable of performing. Kano and his team next hope to test whether or not the animals understand that others have beliefs, desires, intentions, and perspectives that differ from their own.
A still from a short film featuring an aggressive person in an ape suit coming out from a door. The red marks signify tracking of eye movements of an actual non-human primate who was watching the video.
Laughs and smiles in chimps turn out to be far more human-like than previously thought and they date to at least 5 million years ago, suggests a new study on chimpanzee facial expressions and vocalizations. Laughter is not 100 percent identical between the two primates, but people who hear a chuckling chimp usually have little trouble figuring out what the sound generally means. Chimps go "h-h-h," while humans sound more like "ha-ha-ha" or "he-he-he," said Marina Davila Ross, a senior lecturer in the University of Portsmouth's Department of Psychology and lead author of the study in PLOS ONE. Then there is the flexibility of the sounds and related expressions. "Chimpanzees, like humans, can produce their facial expressions free from their vocalizations," Ross explained. "This ability is important for humans. For instance, it allows us to add a smile while talking or laughing, and we can also produce smiles silently. Until now, we did not know that non-human primates also have this ability." It's even possible that the skills first emerged in the common ancestor of chimps and humans.
In both humans and chimps, facial expressions associated with laughter and happiness usually involve an open mouth with a display of teeth. "Open mouth expressions, otherwise known as play faces, or as we call them, laugh faces, typically expose the lower teeth by virtue of the mouth being wide or stretched open," co-author Kim Bard, who is a professor of comparative developmental psychology at the University of Portsmouth, told Discovery News. "We found that there were many types of open mouth expressions, including some configurations with the upper lip drawn up, which sometimes exposes the upper teeth."
Little Callie the chimp, shown in this photo, is enjoying a good laugh with a human friend. Chimps, like people, sometimes laugh and smile when they are alone, too. "We know that laughter and open mouth faces occur mostly during play, but they can occur in solitary play as well as social play," Bard said. "So our current theory is that laughter (in chimps) is typically associated with feelings of joy."
Both young chimps and children tend to laugh and smile a lot, probably because they play more than adults do (and have less to worry about). But why would teeth be exposed as a sign of friendliness? Some experts suspect that the open mouth/exposed teeth expression, during non-threatening play times, allows the other individual to learn how to assess others and to adjust their reactions. Another theory is that a toothy smile often is a visual signal of submissiveness, given that the jaws are usually drawn backward as opposed to the forward thrust of a "grrr" sound and related facial expression.
Since laughter is seen and heard by others, it works wonders as a social bonding tool. In this case, the baby chimp is laughing as its mother tickles its stomach. The researchers suspect that bonobos, like chimps and humans, also benefit from this type of bonding, and have very flexible facial expressions and vocalizations.
So far, observations of chimps show they are always honest laughers, meaning that the sounds function as true signals of joy. People, on the other hand, are notorious for fake laughter. We can smile and laugh as though we are happy, even when we're not. There is, however, a complex twist to chimp laughter: what elicits happiness in some might not in others. "I've seen adolescent males (chimps) who sometimes exhibit bullying behavior, laughing softly while they are picking on another chimpanzee, who is usually not enjoying the interaction," Bard said. "When the victim gets annoyed enough to try to stop the bullying behavior, then the adolescent can respond with greater laughter, which is even more annoying!" "So the laughter is 'joyful,'" she said, "but the adolescent finds picking on another chimpanzee, and even their attempt at retaliation, to be something that brings the adolescent some joy."
Studying the origin of laughter and smiles could help researchers better understand disorders such as autism. This condition is characterized, in part, by difficulties communicating via such signals, and in forming relationships with others. The research also helps us to better understand the abilities of non-human primates, and our evolutionary connections to them. As this image and the one before it show, there's not much difference between a chimp "laugh face" and the typical expression of humans as they enjoy a good guffaw.