Effect of vicarious punishment on stuttering frequency.

This investigation explored the effect of vicarious response-contingent stimulation on the frequency of stuttering. Twenty adult stutterers spoke for 20 minutes, then observed a speaker on a videotape for 10 minutes, and then spoke for an additional 20 minutes. In one condition the speaker on the videotape was a severe stutterer who experienced a dramatic reduction in stuttering under a contingent time-out procedure. In a second condition, the videotape speaker was a severe stutterer who received no experimental manipulations. In the third condition, the videotape speaker was a normal talker who received no experimental manipulations. All subjects participated in all three conditions. Twenty of the stutterers experienced a significant decrease in stuttering as a result of watching the videotape model who received contingent time-out. The subjects did not exhibit significant changes in stuttering after watching the severe stutterer who received no treatment or the normal talker.