Science News - May 19, 2012

“The big idea in social psychology is that social behavior is unconsciously influenced by cues in the environment, but the evidence for that idea needs to be much better,” says cognitive psychologist David Shanks of University College London.

Walk this way

Much of the current fuss over priming concerns Bargh-directed experiments described in an influential 1996 paper. College students unscrambled sentences that, for one group, contained words related to stereotypes about the elderly, such as wrinkle and Florida. Upon finishing, participants who had read old age– related words took about a second longer to walk down an exit hallway than peers who had perused age-neutral words.

A string of unnoticed, stereotypical references to the elderly slyly evoked thoughts of physical deterioration with age, prompting healthy young adults to slow down, Bargh proposed (SN: 10/30/99, p. 280).

Cognitive psychologist Stéphane Doyen of Université Libre de Bruxelles in Belgium has long felt that something was out of step with Bargh’s findings. A team led by Doyen reproduced Bargh’s slow-walk effect, but only when students recruited to lead the experiments were first briefed to expect such responses from participants who read age-related words.

Volunteers primed with elderly stereotypes didn’t change their pace when the experiment’s leaders had no knowledge or expectations about the trials (or when experimenters were told to expect that primed volunteers would walk faster), the team reported online January 18 in PLo S ONE. Taken together, these results suggest that old-age references coaxed students into a leisurely strut only when experimenters provided inadvertent encouragement to slow down, perhaps via facial expressions or body language, Doyen proposes.

Although volunteers reported no awareness of having read words about old age in Bargh’s experiment, they may still have been consciously aware of

the priming, Doyen says. After testing, primed participants in Doyen’s study were shown pictures of four people from different social categories and asked to pick one that could have been related to words used in scrambled sentences. An image of an elderly person was chosen markedly more often than an athlete, an Arab or a physically handicapped individual, suggesting participants were at least somewhat aware that they’d read words about old age.

People may find it difficult to articulate themes associated with words in scrambled sentences even when faintly aware of those themes. “A lot of precautions should be taken to test for unconscious priming effects,” Doyen says.

Even simple experimental actions can give away the game to volunteers. Consider evidence that people judge hills to be steeper after donning heavy backpacks. Investigators initially suggested that a weighty prime on the spine makes terrain look tougher to negotiate, so nearby hills take on added slant.

In a new study directed by psychologist Frank Durgin of Swarthmore College in Pennsylvania, an experimenter told some participants not to let wearing a backpack affect their judgments. Estimates of a hill’s angle were comparably accurate whether these volunteers toted a pack or not. What’s more, many backpack wearers, regardless of what they’d been told, admitted after the trial that they thought the load had been intended to make the hill seem steeper.

Shanks says such findings suggest that recruits for psychology experiments quickly draw conclusions about what’s expected and how to behave, regardless of any unintended signals from researchers. That makes it devilishly hard to study social behavior. Durgin’s study illustrates the need to account for participants’ unspoken assumptions about the purposes of priming trials, Shanks says.

File-drawer rescue

It’s a truly steep climb to cart unsuc-
cessful replications of other scientists’
studies up Mount Publication. Major
journals make no secret of preferring
papers that describe novel advances
and attract media attention, says psy-
chologist Hal Pashler of the University
of California, San Diego. Not surpris-
ingly, failed replications often get filed
and forgotten, meaning studies that sup-
port priming have gotten more attention
than those that don’t.

Do-over data an attempt to replicate a 1996 priming study did not find a difference in how fast volunteers walked after reading words related to old age (top). the do-over, which used infrared sensors to get objective time measurements, did turn up an effect when experimenters were told to expect slow walking (bottom).