A CASCADE OF IMITATION

Led by Robots, Roaches Abandon Instincts

They set up a cockroach arena one yard in diameter. Two six-inch-wide plastic discs were suspended over it, providing the dark shelters that cockroaches prefer to congregate in. But one disc was darker and a more likely cockroach hangout.

When 16 cockroaches were placed in the arena, they naturally gravitated toward the darker disc, following what the researchers believe is an internal calculation of the amount of light and the number of other roaches, finding comfort in company.

Dr. Halloy then replaced four of the cockroaches with four robots equipped with sensors to measure light and the proximity of other robots. When the robots emulated the real roaches, the group continued to seek the dark and crowded place.

When the four robotic roaches were reprogrammed to prefer the lighter disc, however, the real roaches followed them about 60 percent of the time, in essence deferring their own judgment as the preference grew more popular. (The other 40 percent of the time, the robotic roaches succumbed to peer pressure and headed for the darkest place.)

“It’s a cascade of imitation, so a small effect can become quite large,” said Stephen Pratt, a professor of life sciences at Arizona State University. “This one is a real step forward. They’ve developed these theories about what kinds of individual behavior rules would have to follow to generate a collective intelligence. I thought it was very gratifying they could get the roaches to do what they normally would not do.”

See the special robot edition of Science this week for more info, and related articles. Thanks again to Steve for the heads up.

I think that this is the right direction for robot research to go: looking at how to integrate machines into an entrenched social environments. It might be too hasty to suggest that this research provides a reductive, rule-based account of social intelligence, and I am put off by the idea that the robots are best understood as tools for getting roaches to behave the way we want them to. But still, this is exciting research.

Also,

The current research did not test whether the robots could lead the cockroaches to something they really disliked, like broad daylight or insecticide. The results also apply only to cockroaches, Dr. Halloy said. “We are not interested in people,” he said.

Neither am I, Halloy, neither am I.