Verbal Behavior: Extended Edition. Chapter 17: Self-Strengthening of Verbal Behavior. Quote 8 Post author:B. F. Skinner Foundation Post published:January 19, 2026 Post category:Skinner's Quote of the Day Self-probes. A nonverbal probe commonly used by the speaker to encourage his own verbal behavior is a crystal ball or other source of vague visual stimuli. (p. 406) You Might Also Like About Behaviorism, Chapter 7: Thinking, Quote 2 May 12, 2017 Cumulative Record. Chapter 23: Current Trends in Experimental Psychology. Quote 16 June 28, 2023 Contingencies of Reinforcement. Chapter 9: The inside story. Quote 3 September 7, 2018