'Thin-slicing' experience

You’ve likely experienced a near-instantaneous flash of perception when meeting someone for the first time. Perhaps it was a strong feeling you had something in common, a shared interest or similar line of work. You felt an immediate rapid cognition of the experience, and it revealed itself to have been predictive — and accurate. Cognitive psychologists refer to this phenomenon as “thin-slicing,” by which an experience or observation reveals an immediate recognition of a familiar pattern. Within as little as five seconds, individual characteristics are often visible or inferred through the thin-slice peephole.

Thin-slicing, also known as “System 1 processing,” is considered a critical-thinking shortcut (intuitive, inductive, recognition primed). It contrasts with “System 2 processing,” which requires slower, rational, analytic, deductive, rule-based thinking. Examples of System 1 processing are the interviewer who instantly surmises an interview subject is lying, a museum curator who immediately “knows” something isn’t quite right about a recent (expensive) Egyptian museum acquisition, or the fireman on the scene who senses an impending roof collapse and evacuates his team just in time. Yet while thin-slicing can prove to be a vital tool, it’s also one best left in the hands of experts. (See “Critical Thinking and Decisionmaking: Avoiding the Perils of Thin-Slicing,” by Patrick Croskerry, M.D., Ph.D., Annals of Emergency Medicine, December 2006.)