Israel Lieblich

Israel Lieblich was a psychologist at the Hebrew University of Jerusalem where he collaborated extensively with Shlomo Kugelmass and Z. Bergman on psychophysiological detection research during the 1960s and 1970s. He passed away suddenly on September 26, 1986, leaving behind a significant body of work in the emerging field of deception detection. His research was supported by the U.S. Air Force Office of Scientific Research and the Research Fund of the Faculty of Social Sciences at Hebrew University.

Lieblich's primary research contributions focused on galvanic skin response (GSR) as a physiological indicator in deception detection and information concealment. His seminal 1967 study with Kugelmass and Bergman examined "the role of 'lying' in psychophysiological detection," investigating whether the act of lying itself or the significance of concealed information drove physiological responses. He published multiple studies on manipulation of contrast between differential GSR responses through ordered tasks of information detection, and explored GSR detection even in very young children. With Kugelmass and Ben-Shakhar, he examined the efficiency of GSR detection as a function of stimulus set size, contributing to the theoretical understanding of what would later be called the Concealed Information Test (CIT) or Guilty Knowledge Test (GKT).

Lieblich was a core member of an influential Israeli research team that fundamentally shaped modern polygraph science. With Ben-Shakhar, Lieblich, and Kugelmass, he co-authored the landmark 1970 study applying signal detection measures to the Guilty Knowledge Technique, which provided theoretical grounding for arousal theory in deception detection. His 1982 evaluation of polygraphers' judgments from a decision theoretic perspective became widely cited in the field. His 1986 article "Trial by polygraph: Scientific and juridical issues in lie detection" with Ben-Shakhar and Bar-Hillel critically examined both the Control Question Technique and Guilty Knowledge Technique and influenced debates about polygraph admissibility in court.

Beyond deception detection, Lieblich investigated psychophysiological baselines as a function of race and ethnic origin, examining the relation between ethnic origin and GSR reactivity. After his death, his colleagues published a commemorative volume titled "Theory and Application in Psychology: A volume in the memory of Israel Lieblich", testifying to his lasting impact on Israeli psychology and psychophysiological research.