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.
Wallace Craig
Wallace Craig (1876–1954) was an American experimental psychologist and behavior scientist. He provided a conceptual framework for the study of behavior organization and is regarded as one of the founders of ethology. Craig experimentally studied the behavioral expression of emotion, the way innate and learned behavioral tendencies are integrated, and how vocal as well as social behaviors are organized. He encouraged a view of behavior as an integrated process with evolutionary, motivational, experiential, social and ecological degrees of freedom. This integrative perspective helped shape modern behavioral science.