Fruit Flies Pause to Think About Decisions

The fruit fly's tiny speck of a brain has astonished researchers once again. The flies, given the choice of flying into different chambers with varying levels of a scent they associated with danger, lingered longer over the decision as the differences became smaller, showing signs of the same decision-making process that happens in the brains of much larger creatures, including humans, the New York Times reports. Researchers had expected the flies to act completely impulsively instead of taking time to make their minds up.

"This is the clearest evidence yet of a cognitive process running in a very simple brain," the lead researcher tells the BBC. "People tended to think of insects as tiny robots that just respond reflexively to signals from the environment. Now we know that's not true." The link between fly and human decision-making appears to be a gene called FOXP. People—and flies—with defective copies of the gene have trouble retaining enough information to make decisions. "The same mathematical models that describe human decision-making also capture the flies' behavior perfectly," the lead researcher says. "That's remarkable." (Earlier studies have found that fruit flies can perform evasive maneuvers similar to fighter jets—and that male fruit flies denied sex are more likely to consume alcohol.)