Electricity as a medium of psychic life: electrotechnological adventures into psychodiagnosis in Weimar Germany

When electricity became a commodity in 1900, it furnished Germany with new attractions and revolutionized everyday life with all kinds of tools and gadgets; it also opened up a new space for investigating psycho-physical interaction, reviving ideas of a close linkage between psychic life and electricity. The paper traces the emergence of this electro-psychological framework beyond "electroencephalography," the recording of electrical brain waves, to "diagnoscopy," personality profiling by electric phrenology. Diagnoscopy opens a window onto the scientific and public cultures of electricity and psychical processes in Weimar Germany. It garnered enormous attention in the press and was quickly taken up by several institutions for vocational guidance, because it offered a rapid and technological alternative to laborious psychological testing or "subjective" interviewing. Academic psychology and leading figures in brain research reacted with horror; forging counter measures which finally resulted in this technique being denounced as quackery. A few years later, the press celebrated electroencephalography as a mind-reading device, whereas the neuroscientists remained initially skeptical of its significance and the very possibility of an "electroencephalogram" (EEG) before they adapted electroencephalography as a tool for representing various neuro-psychiatric conditions in patterns of recorded signals. The blending of psychophysiology and electrical engineering marks the formation of an electric epistemology in scientific as well as public understanding of the psyche. The transformations of electrodiagnosis from diagnoscopy to the EEG are indicative of a cultural shift in which electricity changed its role from being the power source for experimental apparatuses to becoming a medium of psychic processes.