Behavioral priming, in which behavior is changed by introducing subconscious influences, is a well-established phenomenon, but a new study shows that the cause may be different than what was previously assumed, and that the experimenter's expectations are also crucial for the priming effect to be seen. The results are reported in the Jan. 18 issue of the online journal PLoS ONE.

The study, led by Stephane Doyen of the University of Universite libre de Bruxelles in Belgium, aimed to replicate a seminal behavioral priming study from 1996. In this original study, the authors tested whether subconsciously priming participants to think about age could make them walk more slowly. The participants thought they were volunteering for a word game, in which they had to figure out which word didn't belong, but the actual measure was how fast they left the lab.

The researchers found that when the words that didn't belong were related to being old, the participants walked more slowly after playing the game.

In the new study, however, the experimenters found that the priming effect was only seen when the experimenters' expectations of participant behavior were manipulated as well. The authors emphasize that these results are not simply the results of a self-fulfilling prophecy, but instead appear to reflect environmental cues, such as the experimenter's behavior, which act together with the initial priming from the to affect the participants' behavior.

More information: Doyen S, Klein O, Pichon C-L, Cleeremans A (2012) Behavioral Priming: It's all in the Mind, but hose Mind? PLoS ONE 7(1): e29081. doi:10.1371/journal.pone.0029081