Caffeine’s effects arguably persuasive

Caffeine has long been known to make the heart beat faster, the muscles work harder and the brain focus better. But a new study suggests that it also makes us more open to persuasion when confronted with a point of view that is logical and well-argued.

At the University of Queensland in Australia, researchers ascertained the positions of 148 people on the subject of voluntary euthanasia, then asked each participant to read a position paper that ran counter to his or her beliefs. Before reading the papers, however, half drank orange juice containing the equivalent jolt of two cups of coffee, and half drank plain orange juice.

The results: Compared with subjects who had downed the unfortified juice, the subjects who drank the juiced-up orange drink understood and remembered the counter-arguments better and were more in agreement with those arguments. What’s more, their changed views were unlikely to revert to earlier beliefs later on, when they were asked to read position papers consistent with their original viewpoints.

Pearl Martin, the social psychologist who oversaw the experiments, said subjects hopped up on caffeine paid better attention to well-made arguments and thus appeared better disposed to their logic.

But the nation’s taste for caffeinated drinks should not make us a nation of dupes. “Our research findings suggest that it increases peoples’ ability to correctly evaluate the merits of a particular argument,” said Martin, speaking of caffeine’s effects.