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.
Four Fs (evolution)
The list of the four activities appears to have been first introduced in the late 1950s and early 1960s in articles by psychologist Karl H. Pribram, with the fourth entry in the list sometimes being replaced by other terms such as "sex" or "mating and maternal behavior", although he himself did not use the term "four Fs".