Activity theory
Activity theory (AT; ) is an umbrella term for a line of eclectic social sciences theories and research with its roots in the Soviet psychological activity theory pioneered by Lev Vygotsky , Alexei Leont'ev and Sergei Rubinstein. These scholars sought to understand human activities as systemic and socially situated phenomena and to go beyond paradigms of reflexology (the teaching of Vladimir Bekhterev and his followers) and classical conditioning (the teaching of Ivan Pavlov and his school), psychoanalysis and behaviorism. It became one of the major psychological approaches in the former USSR, being widely used in both theoretical and applied psychology, and in education, professional training, ergonomics, social psychology and work psychology.
Action theory (sociology)
Parsons established action theory to integrate the study of social order with the structural and voluntaristic aspects of macro and micro factors. In other words, he was trying to maintain the scientific rigour of positivism, while acknowledging the necessity of the "subjective dimension" of human action incorporated in hermeneutic types of sociological theorizing. Parsons sees motives as part of our actions. Therefore, he thought that social science must consider ends, purposes and ideals when looking at actions. Parsons placed his discussion within a higher epistemological and explanatory context of systems theory and cybernetics.