On developing a knowledge base in infancy.

Abstract

The development of conceptual categories from 7 to 11 months of age was explored in 5 experiments using an object-examination task. Infants in this age range categorized the global domains of animals, vehicles, and furniture. Plants and kitchen utensils were tested at 11 months, and these domains were also categorized. When 9-month-olds were tested on kitchen utensils, they did not categorize them. Subdivisions within the animal and furniture domains were also examined. Infants did not show any subcategorization of furniture. In the animal domain both 9- and 11-month-olds responded to the life-form distinction between dogs and birds, but they did not differentiate the mammal categories of dogs and cats until 11 months. This early organization of the conceptual system into global domains that become increasingly differentiated is discussed in relation to the adult conceptual system and its breakdown in semantic dementia.

Advancing Downward to the Basic Level

“…This is a somewhat mixed picture compared to the consistent failure of children up to 24 months of age or even older to differentiate mammals on all the tasks we have used. It is also a more mixed picture compared to the failure of infants to differentiate types of furniture on the object examination and sequential touching tests (Mandler et al, 1991;Mandler & McDonough, 1998a). Overall, however, the data suggest that vehicles may be differentiated into subtypes somewhat sooner than furniture.…”

“…More generally, familiarity with the various subclasses of the global domains we have studied may affect the rate at which they become differentiated. Overall, however, the general developmental trend of conceptualization advancing downward from the global to the basic level has been found consistently in our research on this topic (e.g., Mandler et al, 1991;Mandler & McDonough, 1998a, 1998b.…”

“…At the same time, in several experiments we have found that infants seem to know more about vehicles than they do about either animals or household artifacts. First, from 7 to 11 months, infants differentiate cars from motorcycles and airplanes on the object-examination test, although they fail to differentiate different kinds of furniture or different kinds of mammals (Mandler & McDonough, 1993, 1998a. Second, even though 14-month-olds show they have generalized vehicle properties across the entire domain, as illustrated by their using keys on airplanes and forklifts (Mandler & McDonough, 1996), when given the choice they are more likely to choose another member of the same basic-level vehicle category for their imitations than a different basic-level vehicle category (Mandler & McDonough, 1998b).…”

“…Until recently, the hypothesis that basic-level concepts are the first to be formed was typically tested with children 3 years old or older (e.g., Rosch et al, 1976). In the past decade, however, research has begun to show that concept formation has its origins in infancy, and in our laboratory we have conducted a number of experiments indicating that the earliest concepts are broader than the level of dog, table, car, and cup; instead they appear to be at the level of animal (or mammal), furniture, vehicle, and utensil (Mandler & McDonough, 1993, 1996, 1998a, 1998b.…”

The spatial foundations of the conceptual system

“…Subdivision of these domains is one of the ways in which complexity is added to the conceptual system. In some cases di¤erentia-tion involves combining other primitives with already formed concepts, as in land (SURFACE) animals versus air (UP) animals, a subdivision that occurs relatively early in development (Mandler and McDonough 1998a). It is presumably based on the typical location of animals and their paths through space.…”