Researchers Suggest Subliminal Communication May Boost Performance for Simple Tasks

A new study in Science suggests that subliminal communication can motivate participants to expend more energy performing a simple task.

Henk Aarts, a psychologist at Utrecht University in the Netherlands, and colleagues describe their experiment in which they asked participants to squeeze a hand grip for 3.5 seconds after being presented a series of words on a computer screen.

The study participants were first shown either an exertion command like "vigorous," or a series of random letters, for 30 milliseconds. These words were visible for such a brief time that the subjects weren't conscious of seeing them, the authors write. The participants were then shown a consciously visible positive adjective such as "good," or a neutral adverb like "furthermore," for 150 milliseconds. Finally, all participants were asked to squeeze a handgrip.

When the researchers accompanied an exertion command with a positive adjective, the participants had stronger and quicker grips than when they saw random letters or exertion command with neutral adverbs. The authors believe that the presence of positive adjectives—though subliminal—motivated the participants to expend extra effort on the task.

"[The] study demonstrates the human capacity to rely on mental processes in preparing and motivating behavior outside awareness," the authors write in their study published in the 21 March 2008 issue of Science.

The connection between subliminal commands and physical actions—also known as the ideomotor principle—can be used to explain compliance under hypnosis, automatic writing, and dowsing (divining rods), the authors write.

Becky Ham and Benjamin Somers

21 March 2008