Iceberg Theory of Stuttering

A model proposed by Joseph Sheehan (1970) describing stuttering as an iceberg whose visible behaviours - blocks, repetitions, prolongations - are only a small fraction above the waterline. The much larger hidden portion comprises cognitive and affective reactions: avoidance, anticipation, fear, shame, and effort invested in sounding fluent. The iceberg model is widely used by the stuttering community to argue that fluency-centric assessment and external observation miss most of the actual experience of stuttering, with direct implications for therapy, measurement, and AI dataset annotation.