Piaget's theory of formal operations launched empirical work on adolescent cognitive development, with two major outcomes: a lack of confirmation of the key claims of scaling, age of acquisition, and specification of logical requirements; and initiation of further research seeking to identify underlying mechanisms. Important shifts were found in adolescent processing, including speed, working memory capacity, increased inhibitory control, and strategic planning capabilities, all of which continue under the rubric of executive functions. Research on expertise showed it to be an essential component, including the finding that executive functions show improvement in domains where individuals have strong knowledge. More recent is a focus on the context on adolescent cognition, in dual process models that make a distinction between heuristic and more effortful analytic thinking, and also between “hot” and “cool” executive function that varies with the degree of emotional or social investment. Increasing convergence among executive function, dual process models, and developmental neuroscience has focused on the role of myelination in speed of processing, the prominence of the prefrontal cortex (PFC) in judgement and in governance of other neural systems, and the accelerated development of the limbic system, all of which have counterparts in experimental cognitive science. Future work is likely to focus even more directly on the relationship of cognitive and brain development, as imaging technologies rapidly improve.