In a classic passage, Jean Piaget described a young child playing with pebbles and in so doing, discovering principles of mathematics:
“[H]e lined them up in a row, counted them from left to right, and got ten. Then, just for fun, he counted them from right to left to see what number he would get, and was astonished that he got ten again. He put the pebbles in a circle and counted them, and once again there were ten. He went around the circle in the other way and got ten again. And no matter how he put the pebbles down, when he counted them, the number came to ten. He discovered here what is known in mathematics as commutativity, that is, the sum is independent of the order.”(Piaget 1970
By reorganizing, counting, and exploring– all self-directed, all derived from his own actions--the child apparently discerned basic mathematical laws. This humble yet remarkable example illustrates the power of self-directed discovery and learning. Just as Plato’s Meno argued for an intuitive grasp of the principles of geometry in the absence of any mathematical instruction, so too Piaget’s compelling example illustrates the intuitive logic and structure of the child’s untutored mind, attempting to organize experience into a coherent system.
Many years of research following on Piaget’s original insights confirm the active, self-directed nature of childhood cognition (Bruner 1973
; Gopnik & Meltzoff 1997
; Wellman & Gelman 1998
). Moreover, having an opportunity to explore the world actively seems to have direct benefits on interactions and learning. For example, Needham et al. (2002)
find that 3-month-old infants that receive special experience picking up toys with “sticky mittens” (mittens with Velcro, enabling them to pick up objects at any earlier age than they can do otherwise) show more sophisticated engagement with and exploration of objects than infants without the extra experience. Similarly, 3-month-olds with first-hand experience with reaching learn more rapidly than infants who only observe reaching (without actively engaging in this behavior; Sommerville et al. 2005
). It appears, then, that children’s own actions lead to new insights (Kushnir et al. 2008). The self-directed, active nature of early learning is appropriately appreciated, emphasized, and made the focus of study.
Much research on cognitive development focuses exclusively
on children’s knowledge, without asking where such knowledge comes from (Maratsos 2007
). This focus reflects an implicit model of the child as a lone scientist, forming and testing hypotheses on her own. It also reflects a 3-fold assumption that: (1) development concerns structural change, (2) input from others concerns content, and (3) structure is more interesting (i.e., consequential, non-contingent) than content. Certainly, much of the content that children learn from others is relatively contingent or inconsequential (e.g., one’s phone number; the color of barns).
Yet even the most self-directed learning has a hidden level of cultural input, often invisible because it is so pervasive, and thus taken for granted. In the example of pebble-counting above, this input includes a previously learned, culturally sanctioned symbolic system that permits counting (1, 2, 3…), as well as a conventional language system that may have encouraged treating the objects as interchangeable (as all are classified as “pebbles”). Moreover, recent studies of the domain-specificity of children’s theories (e.g., theory of mind; theory of physics) make apparent that content knowledge is integral to structure and development (Wellman & Gelman 1998
; Carey 1985
, in press
Clearly, then, children learn a tremendous amount about the world from the people around them. Moreover, this simple observation sheds light on concept development more broadly when we consider the following questions: What is the nature of that input, and what is the nature of the human mind that allows it to take advantage of that input? How do biases in the child and cues in the environment work together to enable learning?
In this chapter I focus on how children’s concept learning entails learning from others. By “concepts” I mean mental representations that organize experience. Even infants make use of concepts—when smiling at a human face, pointing to the family pet and saying “Kitty!”, or reaching eagerly for a spoonful of applesauce. Although some theorists equate concepts and categories, and consider concepts to be the mental representations that correspond to categories of things in the world, such as dogs or chairs (Margolis 1994
), I would broaden the set to include properties (green, happy), events or states (jumping, wet), individuals (Daddy, Lassie), and abstract ideas (goodness, liberty) (see also Medin et al. 2000
regarding the diversity of human concepts). Although concepts are generally understood to be the building blocks of ideas (e.g., the thought “Lassie is a happy dog” requires possession of the constituent concepts), concepts are also embedded in larger knowledge structures (Gelman 1996
). Concepts therefore cannot be understood wholly as isolated components.
Importantly, the view that children learn from those around them does not mean that children simply, passively take in what they are exposed to (Harris & Koenig 2006
; Callanan 2006
). Any account that presumes children’s concepts are simply the byproduct of what they are exposed to—without active processing or constraints—is problematic in failing to explain how concepts are so similar over individuals and contexts. It also fails to explain how adults (those providing the input) come to have the knowledge they do. One could propose that adults learned their concepts from the input of their own parents, who learned them from their input of their parents, etc., but this simply pushes back the problem to an infinite regress.
Treating children as passively taking in input also would not predict the well-demonstrated phenomenon that children resist counterevidence. A classic example comes from Piagetian training studies, in which children persist in supplying incorrect answers to seemingly simple questions, even following instruction (Ginsberg & Opper 1969
). In the realm of stereotyping, children and adults distort recall to conform to prior assumptions and expectations (Liben & Signorella 1987
). Similar memory and processing biases are found in children’s folk theories of physics, biology, and psychology (Schulz et al. 2007
). Clearly, then, young children actively process the information around them, and are not passive conduits into which information pours.
Thus, I take as a starting assumption that both child biases and environmental input are critical, and that it is important not to characterize concept acquisition processes as exclusively either
innate (Callanan 2006
). Marler (1991)
provides clear evidence from the development of bird-song that innate skeletal frameworks do not preclude learning from experience (see also R. Gelman & Williams 1998
). Parental input and child biases are argued to work together toward a common goal (Markman 1992
), with children’s interpretive biases and parents’ input acting in consistent and mutually reinforcing ways.
The chapter is organized as follows. I begin by sketching out the scope of the problem, arguing that a wide array of concepts require social input, beyond the information children can acquire directly from their senses. I then review several ways that language serves a particularly important role in conveying conceptual information to children: through testimony, through naming, and through covert categories. Childhood essentialism is reviewed as a belief system that is informed by explicit and implicit language input. This brings us to the critical issue of children’s credulity and skepticism, where the research evidence indicates a mixture of sensitivity and selectivity to the social information that surrounds them. From here I address the question of how children come to distinguish between reliable vs. unreliable information, how and when children distinguish fiction and pretense from fact, and the extent to which different, seemingly competing explanatory systems co-exist in early childhood. Finally, I consider a number of open questions, before summarizing and concluding.