Thin-slicing

Thin-slicing is a term used in psychology and philosophy to describe the ability to find patterns in events based only on "thin slices," or narrow windows, of experience. The term means making very quick inferences about the state, characteristics or details of an individual or situation with minimal amounts of information. Brief judgments based on thin-slicing are similar to those judgments based on much more information. Judgments based on thin-slicing can be as accurate, or even more accurate, than judgments based on much more information.

The first recorded use of the term was in 1992 by Nalini Ambady and Robert Rosenthal in a meta-analysis in the Psychological Bulletin. Since then, thin-slicing has been applied to many domains, and has been used to make various types of judgments. A non-exhaustive list of domains includes interpersonal relationship, clinical studies, education, etc.

Thin-slicing refers to observing a small selection of an interaction, usually less than 5 minutes, and being able to accurately draw conclusions about the emotions and attitudes of the people interacting.

Thin slices of the behavioral stream contain important diagnostic and predictive social psychological information. Because thin-slice perception and judgment is sufficiently effective, people's interpersonal perceptions can occur immediately, automatically, and to some extent validly before much can be communicated verbally or through actions and events. Given the limited conditions under which social inference and correction occur, these initial judgments may determine people's ultimate perceptions, evaluations, and theories about those with whom they interact face-to-face.

Many studies have shown that brief observations can be used to assess outcomes at levels higher than expected by chance. Once comparing these observations of less than five minutes to those greater than five minutes, the data show no significant change, thus implying that observations made within the first few minutes are unchanging. An example of this can be seen in an Ambady and Rosenthal experiment in 1993, in which they assessed the effect of thin slicing with 2-, 5-, and 10-second clips of non-verbal behaviors of teachers and the viewers' ratings of those teachers afterwards. Impressions formed after viewing thin slices of behavior are considered accurate if they match impressions formed after a more detailed observation of the subject and if they match the impressions formed by other raters. While people are often not able to report the factors that influence their judgments, researchers identify types of information in brief slices of behavior that are responsible for accurate judgments. Types of information include visual and verbal information. More specifically, researchers look at how people make judgments based on their observations of others' minor traits such as eye contact, fidgeting, open-handed gestures, stiff posture, smiling, etc. Behaviors such as frowning, fidgeting, and gazing down had poor ratings for traits describing the teacher's confidence, warmth and optimism while teachers with positive ratings for these traits smiled more, were more likely to walk around and touch their upper torsos.

...
Wikipedia