Pigs are highly intelligent creatures, and a study released on Thursday has revealed that they’re skilled gamers, too.
Published in the journal Frontiers in Psychology, the paper is the culmination of extensive research into pig intelligence that began in the ’90s by scientists working with Stanley Curtis, a “legendary swine researcher” who died in 2010. It was co-authored by Candace Croney, director of Purdue University’s Center for Animal Welfare Science, and Sarah Boysen, a professor of psychology at Ohio State University renowned for her research into chimpanzees.
The paper highlights two Yorkshire pigs named Hamlet and Omelet, and two Panepinto micro pigs — often used in research and usually weighing 50-70 pounds — named Ebony and Ivory, all of whom were kept at Pennsylvania State University.
The pigs were trained at a “rudimentary joystick-operated video game task” that had originally been created to test chimpanzees and rhesus monkeys. They learned how to manipulate a joystick with their snouts to move a computer cursor across a screen. Once they maneuvered the cursor to hit a wall, a treat dispenser connected to the joystick would deliver a snack.
The game had varying difficulty levels, and the number of walls that appeared on-screen decreased from four to one. The pigs, all of whom were far-sighted, eventually excelled at the game, though their performance varied at the higher difficulty levels. (Ivory hit the one-walled target an impressive 76% of the time, for instance.)
Hamlet and Omelette were also forced to retire after 12 weeks of training because “they had grown too large to stand long enough to complete sessions.”
“That the pigs achieved the level of success they did on a task that was significantly outside their normal frame of reference in itself remarkable, and indicative of their behavioral and cognitive flexibility,” the study states, pointing out that even when the joystick broke, the hogs “continued to make correct responses when rewarded only with verbal and tactile reinforcement from the experimenter, who was also their primary caretaker.”
All of the pigs involved in the study — aside from Omelette, who developed health issues and had to be euthanized — lived well following their careers as gamers. Hamlet spent the rest of his life on a bed and breakfast farm, while Ebony and Ivory retired to a children’s zoo, Croney said.
Hamlet also appeared in a short documentary originally produced by the BBC that is now visible on the YouTube account of advocacy group Compassion in World Farming. The film compared his gaming prowess with that of a Jack Russell terrier that struggled to master the joystick game even after a year of training.