Conceptual Development

concepts, conceptual networks, and structurally organized domains of knowledge). The simpler forms may establish the foundation for the more complex ones. Principle 2: Simpler Forms Are More Universal; Complex Forms Are More Unique Simpler forms of conceptual behavior are more universal: They exhibit early onset and a relatively shallow developmental curve. They also present in a variety of species. Trim Size: 8.5in x 11in Lerner c12.tex V1 Volume II 08/11/2014 9:57am Page 512 512 Conceptual Development In contrast, more complex forms are likely to be uniquely human: They exhibit later onset and marked development. In addition, more complex forms of conceptual behavior are likely to depend on other aspects of cognitive development, including the development of attention and memory. Principle 3: Complex Forms of Conceptual Behavior Are Likely to Be Affected by Language and Instruction Whereas simpler forms of conceptual behavior are independent of language or instruction—as demonstrated by the ability of nonlinguistic organisms (animals and prelinguistic infants) to perform these behaviors—the more advanced forms of conceptual behavior may depend critically on language and instruction. Language is particularly important for acquisition of abstract concepts denoting unobservable or even fictitious entities and for the development of conceptual networks. Some of these abstract concepts may also require instruction. For example, it is difficult to imagine how scientific, mathematical, or legal concepts and conceptual networks within these domains can be acquired without both language and instruction. Although language and instruction may not be sufficient for acquiring these concepts, both seem to be necessary. Principle 4: The Structure of Input Matters In learning of new categories, the structure of input matters: Categories that are based on multiple featural overlap (and thus statistically dense) are easier to learn without instruction than are categories that are based on few defining features. Therefore, learning of statistically denser categories exhibits early onset, is present in a broad variety of species, and does not require instruction. In contrast, learning of more statistically sparse categories exhibits later onset, may be limited to organisms with a functioning prefrontal cortex, and may require instruction. Also, as has been shown by computational work (e.g., Hills et al., 2009; Landauer & Dumais, 1997), structure may also stem from language, especially for those concepts that lack perceptual structure. Principle 5: Conceptual Development Progresses From Less Structured Representations to More Structured Representations Many of the early appearing, simpler conceptual behaviors are based on similarity or featural overlap among the to-be-grouped entities. Therefore, although structure transpires across the entities (in that they have features in common), there is little structure across the categories. At the same time, semantic development may include the development of conceptual networks (and possibly domains of knowledge), with increasing coherence in relations within the network, and greater distinction among the networks. CONCLUDING COMMENTS: FUTURE OF RESEARCH ON CONCEPTUAL DEVELOPMENT Given the long history of research on conceptual development, it is useful to ask, Where is the field now and where it is going? Although the ability of humans to acquire and use concepts of various degrees of complexity is well established, the origins of this ability, its ontogenesis, and its neurobiology are not well understood. Therefore, our remaining challenge is to understand the links among developmental, cognitive, and brain processes of conceptual behaviors, thus developing a deeper, more complete understanding of the ability so central for our intelligence. Three issues seem to be critical in our understanding of concepts and their development: structure and mechanism, development, and biological foundations. Structure and Mechanism One of the major challenges in understanding conceptual development is to develop a more complete knowledge of how concepts are learned, represented, and integrated into interconnected structures and then, in turn, how individual concepts and parts of the structure are used in reasoning and problem solving. At present, we have a variety of theories of category learning and a variety of theories of conceptual structure, but no integrated theoretical framework. Developing such a framework would substantially advance our understanding of conceptual behaviors and conceptual development.