A term from operant conditioning, set out by C. B. Ferster and B. F. Skinner in Schedules of Reinforcement (Appleton-Century-Crofts, 1957) and cited in The Invisible College under the variant title Patterns of Reinforcement. The finding that matters here is that intermittent reward, delivered on a schedule combining periodicity with unpredictability, produces learning that is slower to establish than continuous reward and far harder to extinguish.
Jacques Vallee applies it to the sighting record. The quantitative heart of the book is a single graph, Figure 3, the 1947 to 1962 wave index with the long-term trend removed, over which he asks whether the waves are a reinforcement schedule operating on a whole society, producing belief that is slow, continuous and effectively irreversible. It is the sharpest reframing in the book and the point at which the Control System Hypothesis stops being a metaphor and starts making a testable-sounding claim.
The objection is to the data rather than the idea. The index is assembled from weighted sighting counts and read by eye rather than tested statistically, and sighting waves in this field are known to track media attention, which supplies an ordinary mechanism for the same shape.
Connections
Control System Hypothesis · Jacques Vallee · The Invisible College