Nalini Ambady and Robert Rosenthal led the quest to understand the limits of impression formation, and in a series of studies they demonstrated that observers make accurate personality and competency judgments using very “thin slices of behavior.” In their experiments, undergraduate raters watched brief, 30-sec video clips of teachers in the classroom, and evaluated the teachers on thirteen different variables, including likability, competence, warmth, honesty, and optimism. Notably, the audio on these video clips was removed, so that raters made their evaluations exclusively on the basis of non-verbal cues. Not only were the judgments of the teachers fairly consistent across raters, but they were also fairly accurate.
These appraisals, rendered after only half a minute of observation, were reliably predictive of the evaluation scores given to the teachers by students whom they had instructed for a full semester. In subsequent studies Ambady and Rosenthal examined judgments rendered after only ten seconds, and then after a mere two seconds. Even when given only two seconds of silent video, the raters made judgments that correlated reliably with end-of-semester evaluations made by the teachers' own students.
Two seconds of silent video may indeed seem like a very thin slice of behavior upon which to base an impression, but researchers have demonstrated that we can do well with far less. More recent investigations have demonstrated that a simple photograph of our favorite shoes provides enough data for strangers to judge our age, gender, income and attachment anxiety, and that a list of our top ten favorite songs reveals how agreeable and emotional stable we are.
But what if we reduce the information available to a mere series of dots, strung together to form a stick figure that depicts movement but nothing else? John Thoresen, Quoc Vuong, and Anthony Atkinson addressed this question in a series of experiments where participants judged personality traits on the basis of body movements alone. The scientists first videotaped male and female volunteers as they walked roughly 25 feet. From these videos, they created stick-figure depictions of each walker, eliminating all information about age, attractiveness, weight, clothing, race, and gender. The only information available to observers was the gait of the walker, conveyed in the form of a two-dimensional stick-figure.
Participants in these studies rated each stick-figure walker on six trait scales: adventurousness, extraversion, neuroticism, trustworthiness, warmth, and approachability. Two questions were addressed: First, were the impressions about the stick-figure walkers consistent across raters? Second, were they accurate?
Raters were in fact fairly reliable in their judgments: if one rater judged a walker to be adventurous and extraverted, it is likely that other raters did too. Despite the consensus in ratings, though, the impressions were not correct. The trait judgments made by raters did not align with the walkers' self-reports.
These findings are a bit puzzling. If the raters were wrong, why were their impressions so similar? What information were raters using to make their judgments that lead to such consistency? Thoresen and colleagues speculated that the raters may have tried to glean other (unseen) physical characteristics of the stick-figure walkers like gender, age, or health, and may have used those intuitions as the basis for their personality judgments. To test this possibility, Thoresen and colleagues thus asked new groups of raters to view the stick-figure walkers and guess various physical characteristics of the stick-figure walkers, like gender, attractiveness, age, and excitability.