"Our colleagues who had done work with primates told us not to worry about this step," Curtis says. "And indeed [Hamlet and Omelette] learned that very quickly."

The final hurdle involved teaching the pigs to line up the cursor with an icon on the screen. Again, Curtis turned to the reward method. He installed a machine that would automatically deliver an m&m every time the pigs performed the routine correctly. It took just a few hours for Hamlet and Omelette to figure out the trick.

Curtis says the pigs learned to play the simple games every bit as quickly as primates. In fact, Hamlet and Omelette exhibited more interest in the task at hand than their primate cousins.

"They weren't just lever-pressing on the joystick," says Bill Hopkins, a professor at Berry College in Rome, Georgia. As a researcher at the Yerkes Primate Center in nearby Atlanta, Hopkins has been doing similar work with chimpanzees and other apes for several years. "They looked like they were catching on that there was more to it," he says. "They looked engaged."

About the only problem so far is one of attention span: About 15 minutes into a videogame session, Hamlet and Omelette usually get tired of playing and lie down. Chimpanzees, on the other hand, play for hours on end.

The pigs are still far from being very accurate, but the work is promising, Hopkins says. "If the animals reliably develop the use of this system, down the road I think some really interesting stuff could be coming out of this."

This summer, Curtis plans to train two other pairs of pigs to play videogames. Taking them through the initial stages faster, Curtis hopes the new pigs will take to videogames with renewed vigor.

In the future, Curtis will focus on more challenging exercises to see if pigs can pick between several characters or icons that represent objects. That would constitute a rudimentary form of symbolic language. With similar techniques, primates have been able to express themselves in "languages" with a vocabulary of up to 500 words.

"I'm not surprised that pigs are pretty bright and capable," says Curtis, who over years of watching the animals became convinced pigs were among the most intelligent farm animals.

"But I was gratified by it," he says. "We think human beings are pretty special. And we believe the nonhuman primates [because of the resemblance to humans] should be rather special, too. When a pig can learn things as quickly as chimpanzees, that's remarkable."

Some pigs.

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Teaching Complex Mechanics, Naturally
by Alex Huneeus