Jung, Luria, and Lie Detection

The basic formula in lie detection, and the first thing verification specialists learn, is stimulus – processing – reaction. These concepts were explored in scientific research by Carl Gustav Jung through his associative experiment, and by our compatriot Alexander Romanovich Luria, who introduced his reactological theory of affective behavior.

Jung’s Associative Experiment

Jung’s associative experiment emerged in the early twentieth century, during a period when psychoanalysis actively used the method of free associations to access the unconscious layers of the psyche. Jung noticed that people took longer to respond to certain words in an associative series than to others. A delay in the normal associative reaction time by more than two and a half times usually indicated that these associations touched on the person’s affective-emotional sphere. Deviations from the usual flow of associations (for example, “pencil–paper,” “night–dark”) were also signs that the topic was significant for the individual.

Luria’s Research on Affective Behavior

Around the same time, Luria became interested in a similar topic. He observed that affective-emotional experiences influenced not only reaction speed but also overall behavior, manifesting in specific movements—facial expressions, gestures, and speech. This led to the development of the “method of conjugated motor reactions.” In his experiments, Luria asked subjects to make hand movements, such as pressing buttons with both index fingers, simultaneously with their verbal responses. The motor activity associated with affective processes always showed signs of sharp excitement: the pressure curve became jagged, marked by abrupt, trembling movements.

From Experiments to Modern Lie Detection

Thus, both in Jung’s associative experiment and in Luria’s research, the goal of experimental diagnostics was to be able to present stimuli that would cause reaction disturbances and to objectively observe and record these disturbances.

Today, these observations are actively used in both polygraph work and non-instrumental lie detection methods. Assessing reaction speed, observing nonverbal behavior, and identifying physiological signs of stress form the foundation of a verifier’s work. Jung used a stopwatch, Luria used a device to record motor changes, and for us, our main tools are attention and observation.