Cultural-historical activity theory
Cultural-historical activity theory (CHAT) is a theoretical framework to conceptualize and analyse the relationship between cognition (what people think and feel) and activity (what people do). The theory was founded by L. S. Vygotsky and Aleksei N. Leontiev, who were part of the cultural-historical school of Russian psychology. The Soviet philosopher of psychology, S.L. Rubinshtein, developed his own variant of activity as a philosophical and psychological theory, independent from Vygotsky's work. Political restrictions in Stalin's Russia had suppressed the cultural-historical psychology – also known as the Vygotsky School – in the mid-thirties. This meant that the core "activity" concept remained confined to the field of psychology. Vygotsky's insight into the dynamics of consciousness was that it is essentially subjective and shaped by the history of each individual's social and cultural experiences. Since the 1990s, CHAT has attracted a growing interest among academics worldwide. Elsewhere CHAT has been described as "a cross-disciplinary framework for studying how humans transform natural and social reality, including themselves, as an ongoing culturally and historically situated, materially and socially mediated process". CHAT explicitly incorporates the mediation of activities by society, which means that it can be used to link concerns normally independently examined by sociologists of education and (social) psychologists. Core ideas are: 1) humans act collectively, learn by doing, and communicate in and via actions; 2) humans make, employ, and adapt tools to learn and communicate; and 3) community is central to the process of making and interpreting meaning – and thus to all forms of learning, communicating, and acting.
The term CHAT was coined by Michael Cole and popularized by Yrjö Engeström to promote the unity of what, by the 1990s, had become a variety of currents harking back to Vygotsky's work. Prominent among those currents are Cultural-historical psychology, in use since the 1930s, and Activity theory in use since the 1960s.