A two-day experiment by Nagasaki Bio Park and arcade operator Wide Leisure tested whether monkeys, specifically the tufted capuchins, a highly intelligent species often featured in movies, can understand and play crane games.
The crane game machine had been modified so that the monkeys do not injure themselves while playing. The machine was also made to better suit the abilities and needs of the monkeys, including removing the use of coins to activate the game — it would simply start when someone moves the joystick — and changing the rewards to raisins.
With everything in place, it was time to teach the monkeys about crane games. The Bio Park staff first showed them a video on a tablet of someone playing a crane game and winning a prize. But it was difficult for them to make the connection to the machine in their enclosure.
The staff then demonstrated on the monkeys’ machine to show that they could get raisins from the game. But the first day of the experiment ended with failure as the monkeys seemed to have trouble replicating the process.
On the second day, however, a monkey named Daiju managed to operate the machine and won himself some treats. To top it off, he was able to repeat the process, proving that it was not a one-off lucky attempt. He actually understood that moving the joystick would cause the claw to move and give him raisins!
Below is the full experiment video, in Japanese only. Check out 6:01 for the moment of triumph.