Users of digital platforms such as Google, Instagram, Facebook, and Amazon are regularly exposed to more or less subtle forms of algorithmic control, which, as Thomas Berns and Antoinette Rouvroy have emphasised, is based on “the automated collection, aggregation and analysis of big data so as to model, anticipate and pre-emptively affect possible behaviours” (Berns/Rouvroy 2013). In this context, social psychologist Shoshana Zuboff speaks of the exploitation of “behavioral surplus”: interests, emotions, and personality patterns become a resource for data extraction, on the basis of which users’ behaviour can be profitably guided and controlled (Zuboff 2019: 21). Awareness of such forms of subliminal control—for which the methods of predictive artificial intelligence stand as the most recent example—is, depending on users’ level of knowledge, barely or only slightly developed. This brief article aims to place today’s digital technologies for predicting and influencing behaviour within the context of a history of “Psychotechnics“ that dates back over a century. Drawing on a self-proclaimed science of “psychological influence and control” (Münsterberg 1914: 136), in his 1914 work Grundzüge der Psychotechnik Hugo Münsterberg outlined a programme for shaping virtually every aspect of human life. A careful reading of Münsterberg’s writings today is enlightening in that they reveal the connection between the early history of psychological experimentation and the ideological programmes of eugenics—a heritage, that arguably laid the groundworks for today’s psychological approaches to how humans interact with technology.