People are remarkably smart: They use language, possess complex motor skills, make nontrivial inferences, develop and use scientific theories, make laws, and adapt to complex dynamic environments. Much of this knowledge requires concepts and this study focuses on how people acquire concepts. It is argued that conceptual development progresses from simple perceptual grouping to highly abstract scientific concepts. This proposal of conceptual development has four parts. First, it is argued that categories in the world have different structure. Second, there might (...) be different learning systems that evolved to learn categories of differing structures. Third, these systems exhibit differential maturational course, which affects how categories of different structures are learned in the course of development. And finally, an interaction of these components may result in the developmental transition from perceptual groupings to more abstract concepts. This study reviews a large body of empirical evidence supporting this proposal. (shrink)

We argue that the Rules-Similarity continuum is only a useful formalism for particular, isolated tasks and must rest on the assumption that representations formed during a particular task are independent of other tasks. We show this to be an unrealistic conjecture. We additionally point out that describing categorization as selective weighing and abstracting of features misses the important step of discovering what the possible features are.

We review the relationships between language, inner speech, and cognitive control in children and young adults, focusing on the domain of cognitive flexibility. We address the role that inner speech plays in flexibly shifting between tasks, addressing whether it is used to represent task rules, provide a reminder of task order, or aid in task retrieval. We also consider whether the development of inner speech in childhood serves to drive the development of cognitive flexibility. We conclude that there is a (...) close association between inner speech and cognitive flexibility in both adults and children. Experimental work has begun to specify in detail the role that inner speech might play in adult performance, suggesting that language plays a facilitative but not essential role in representing and activating the relevant task set, processes that occur on both switch and nonswitch trials. While developmental studies suggest an increase in the spontaneous use of verbal strategies with age, implying an increase in top-down control during shifting, experimental work is needed to specify more precisely the nature and precise role that inner speech plays in the development of cognitive control through childhood. (shrink)