Charlie Brooker’s television series Black Mirror featured an episode about a CGI bear named Waldo that misled a political revolution built on fart sounds and crass imagery. Another CGI Waldo has cropped up in some recent research into contagious yawning in orangutans. This animation, however, is less into satire and more into science, as Waldo was tasked with yawning in front of live orangutans to see if it made them let one rip (get your heads out of the gutter, I meant yawn).
You’ll likely have noticed yourself that yawning is highly contagious, even reading or thinking about it can have most of us… feeling one… coming on! Interestingly, we’re not the only species who can “catch” a yawn. It’s even been noted among elephants, who will yawn if their human handler does.
This new research, published in the journal Scientific Reports, wanted to touch on the hypothesized link between contagious yawning and sociality, as it seems to be a trait mostly present in social species. Chimpanzees and bonobos are both affected by the phenomenon, but gorillas don’t exhibit contagious yawning. Until now, the ability to make orangutans catch a yawn hadn’t been studied. As one of the least social close relatives to Homo sapiens, they present as an interesting subject in identifying how early on in apes this behavior evolved.
To find out if orangutans yawn contagiously, the researchers showed videos of other orangutans yawning to their experimental subjects. They then also showed them a video of Waldo, the 3D orangutan avatar, yawning in the same way.
They carried out 700 trials, and found that orangutans did indeed catch a yawn from the videos they were shown. Interestingly, the contagiousness of a yawn endured regardless of whether or not the orangutan in the video was familiar or unfamiliar. Waldo, however, had little influence over the need to yawn for the orangutans, perhaps because they were put off by the uncanny valley effect.
“Yawning is an evolutionarily old phenomenon as its associated motor features can be recognized in different groups of animals,” wrote the study authors. “While a yawning-like pattern is observed in a wide range of vertebrates, contagious yawning is less wide-spread. To date, [contagious yawning] appears to be present in only a few, generally social species.
“Our findings contribute to understanding the evolutionary basis of [contagious yawning] in hominids by showing that orangutans, like humans, chimpanzees, and bonobos, yawn contagiously.”