Japanese researchers have made two short films, both involving a gorilla suit. They have shown them to a bunch of bonobos and chimpanzees. Why? By tracking the animals’ eye movements, they claim to have got inside the minds of apes.

The two films are certainly the highlights of this study, “half-minute movie clips depicting novel and potentially alarming situations for the participant apes.” These apes, captive animals at the Kumamoto Sanctuary in Japan, “have some experience watching commercially available films and TV programs since youth,” the researchers write in Current Biology.

The first film is called “King Kong Attack” and involves two smiling, waving humans, some bananas and the sudden entry of a mysterious third character – a human dressed in a King Kong gorilla suit and wellington boots. It is funny and alarming in roughly equal measure.

Facebook Twitter Pinterest King Kong Attack. Warning: contains a moment of mild peril

The apes in the study got to watch the film twice, the second showing coming 24 hours after the first. The researchers wanted to know whether, on second viewing, the apes anticipated the entrance of King Kong. It’s not that obvious from the video, but according to the analysis the subjects spent significantly more time watching the appropriate door in the seconds prior to the dramatic entry of the gorilla-suited researcher.

The sequel is called “Revenge to King Kong” and attempts to examine whether the chimps and bonobos are actually engaged in the content of the movie. A researcher plays nicely with King Kong, who suddenly and inexplicably goes on the rampage. The human responds by choosing a weapon – a hammer or sword – and delivering savage revenge on naughty King Kong.



Facebook Twitter Pinterest Revenge to King Kong. Warning: contains a scene of violence towards a human in a gorilla suit

As before, the researchers showed the apes the movie twice, but on the second viewing they switched round the position of the hammer and sword. If the chimps and bonobos were paying attention to the content of the movie, they should focus on the weapon used during the first showing in spite of the fact that it was now in a new location. They did.

“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,” says lead author Fumihiro Kano of Kyoto University in Japan. “Our results thus show that great apes, just by watching the events once, encoded particular information (location and content) into long-term memory and later retrieved that information at a particular time in anticipation of the impending events,” he and his colleague write.

This won’t come as much of a surprise. But the approach of studying anticipatory glances to infer cognitive processes in a non-human animal is quite exciting. With the right storyboard, for instance, it should be possible to study what apes understand about the beliefs, desires and intentions of others. “Understanding stories requires a lot of cognitive abilities,” says Kano. “So if we use stories then we can examine their higher-level cognition.”

There is no mention of popcorn in the research paper, though the methods section does note that “apes were allowed to chew fruits or drink juice during the recording.”

Kano, F. and Hirata, S. (2015) Great apes make anticipatory looks based on long-term memory of single events. Current Biology