Reliability and validity of nonverbal thin slices in social interactions.

Four studies investigated the reliability and validity of thin slices of nonverbal behavior from social interactions including (a) how well individual slices of a given behavior predict other slices in the same interaction; (b) how well a slice of a given behavior represents the entirety of that behavior within an interaction; (c) how long a slice is necessary to sufficiently represent the entirety of a behavior within an interaction; (d) which slices best capture the entirety of behavior, across different behaviors; and (e) which behaviors (of six measured behaviors) are best captured by slices. Notable findings included strong reliability and validity for thin slices of gaze and nods, and that a 1.5-min slice from the start of an interaction may adequately represent some behaviors. Results provide useful information to researchers making decisions about slice measurement of behavior.