Development: Intelligence/Cognitive

Introduction

Cognitive development is the study of how fundamental processes of acquiring knowledge and information about the self and environment develop. The evaluation of cognitive development, known as cognitive assessment, is an important part of monitoring normal child development. The study of cognitive development, indeed the roots of cognitive assessment, can be traced to the French psychologist Jean Piaget (1896–1980). In many respects, Piaget's theories formed the basis for the modern study of cognitive development. Although not all of Piaget's tenets have withstood the test of time, they continue to influence modern cognitive assessment, if only conceptually (Wadsworth, 1996). Here we will briefly describe Piaget's theory of cognitive development as well his observations of the A-not-B tasks. Finally, we will illustrate the modern tools of cognitive assessment with the Bayley Scale of Infant Development, two Slosson tests, and the Kaufman Adolescent and Adult Intelligence Test (KAIT).

Four Stages of Piaget's Theory

In 1920, Piaget began testing infants and children to see at what age they could solve certain problems correctly and how they did so. Based on his observations, Piaget became more interested in the children's errors on specific tasks which he noticed occurred at distinct ages of development for the majority of children tested. Piaget's first developmental stage, the sensorimo-tor stage, encompasses the first two years of life. During this stage, the infant uses the motor movements and sensory stimulation of touching, mouthing, looking, and other actions to organize the properties of its environment. It is through these interactions with the environment that the infant begins to develop schemas. Piaget believed that sensorimotor stage infants lacked cognition; in other words, infants did not think about the environment, they merely organized it. Most patterns of infant behaviour are dominated by reflex. After eight months, the infant begins to develop the concept of object permanence, or the awareness that an object still exists despite its being taken from view. By the end of the second year, the infant begins to have internal representations of objects and events and understand that objects may affect the environment as the infant can (Halford, 1978).

Piaget's second stage, the pre-operational stage, encompasses ages 2 through 6 or 7 years. In this stage, the child begins to represent objects and events symbolically through, for example, representational behaviours such as symbolic play, drawing, and mental image memory. Language develops rapidly during this period. As the child progresses through this stage, language is increasingly used as a social tool and moral feelings and reasoning start to develop. However, thoughts and language are largely egocentric with the child having difficulty distinguishing perception and logical reasoning. As a result, the capacity for structured conversation is not yet apparent. Affective and social schemata are continuously assimilated and accommodated throughout this stage (Inhelder & Piaget, 1958; Piaget, 1972).

Piaget believed that a third process, equilibrium, prevented an extreme use of either assimilation or accommodation to classify stimuli. Equilibrium is a self-regulatory mechanism that created a balance between accommodation and assimilation. When schemata cannot assimilate to a new stimulus or situation, the child is said to be in a state of disequilibrium. As the schemata adapt to the new stimulus, a cognitive balance is achieved, or equilibrium. This process is referred to as equilibration (Piaget, 1977). In combination, these three processes facilitate cognitive development throughout an individual's life.

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