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.
Trait activation theory
Trait activation theory is a personality theory of work performance based on the concept of trait activation, and is derived from an integration of trait theory, situationism, and personality-job fit theory. 
"Trait theory" is a psychological approach that includes studying personality traits as relatively stable individual differences which describe general predispositions or predictable common patterns of thinking and experiencing emotions that influence behavior. In fact, personality traits have been associated with important life outcomes (see Personality and life outcomes). The most well-known description or categorization of personality traits is called the "Big Five personality traits" which includes five broad personality dimensions: conscientiousness, extraversion, agreeableness, openness, and neuroticism (or, in its inverse form, emotional stability).
In personality psychology there has been a long-standing person-situation debate wherein trait theorists suggested behavior could be predicted by analyzing consistent personalities across situations, but "situationists" disagreed that personalities were as consistent as trait theorists suggested. "Situationists" argued that the external situation – not general traits – was what influenced behavior. Today, most personality psychologists adhere to an interactionist perspective, where both person and situation contribute to human behavior; as a result, the primary debate no longer exists.