Recent Issues. Chapter 12: The Behavior of Organisms at Fifty. Quote 15 Post author:B. F. Skinner Foundation Post published:April 19, 2019 Post category:Skinner's Quote of the Day “When a response was reinforced only in the presence of the light as an S Dee, the rat responded slowly in its absence (which, unfortunately, I called S Delta, hard to print) but responded immediately when the light came on.” (p. 127) You Might Also Like Cumulative Record. Chapter 5: “Man”. Quote 9 February 1, 2022 Verbal Behavior: Extended Edition. Chapter 14: Composition and Its Effects. Quote 6 October 9, 2025 Cumulative Record. Chapter 14: Why We Need Teaching Machines. Quote 8 November 25, 2022