Thin-Slicing

Thin-slicing, established by Ambady and Rosenthal's 1992 meta-analysis, is the finding and method that judgments based on very brief samples of expressive behavior -- sometimes only a few seconds -- can predict consequential interpersonal outcomes with surprising accuracy. In the paradigm, short clips (thin slices) of a target's nonverbal and verbal behavior are shown to naive observers who rate a trait or quality, and these ratings are correlated with an independent criterion such as teaching effectiveness, clinical skill, rapport, or relationship outcomes. Ambady and Rosenthal showed across many studies that thin-slice judgments are reliable and valid, and that lengthening the observation often adds little accuracy. The method became a key tool for studying interpersonal perception, first impressions, and the information carried by brief behavioral displays, while also raising questions about the bases and biases of rapid social judgment.