Page:CIAdeceptionMaximsFactFolklore 1980.pdf/21

C00036554 of actors to detect small changes in observables, even if the cumulative change over time is large. This is the counterpart to Jervis' Hypothesis #3 (26), "actors can more easily assimilate into their established image of another actor information contradicting that image if the information is transmitted and considered bit by bit than if it comes all at once." This is the basis for the use of conditioning as a deception technique.

Conditioning or gradual acclimatization has an important place in the design of deception schemes. There are numerous instances of its succcessful application. One now-classic application of this principle was made in the breakout of the German ships Scharnhorst, Gneisenau and Prinz Eugen from Brest on 12 February 1942. The breakout was facilitated by jamming the British radar. Ordinarily this would have been a significant tip-off that something was amiss, but the British radar operators dismissed it as caused by atmospheric disturbance. This error was the result of a carefully orchestrated German ruse directed by General Wolfgang Martini, the Head of the Luftwaffe Signals Service. As Potter (27) observed:

At dawn each day during January English radio stations had a few minutes or jamming, deliberately