MARY STEVENSON CASSATT, Mother and Child, 1900

BROOKLYN MUSEUM OF ART, NEW YORK, USA/THE BRIDGEMAN ART LIBRARY

our–month–old Benjamin, perched on the kitchen counter in his infant seat, is watching his parents wash the dinner dishes. What he observes includes two people who move on their own, as well as a variety of glass, ceramic, and metal objects of differing sizes and shapes that move only when picked up and manipulated by the people. Other elements of the scene never move. As the people go about their task, distinctive sounds emanate from their moving lips, while different sounds occur as they deposit cutlery, skillets, glasses, and sponges on the kitchen counter. At one point, Benjamin sees a cup completely disappear from view when his father places it on the counter behind a cooking pot; it reappears a moment later when the pot is moved. He also sees objects disappear as they pass through the suds and into the water, but he never sees one object pass through another. The objects that are placed on the counter stay put, until Benjamin's father puts a crystal goblet on the counter with more than half of its base hanging over the counter's edge. The crashing sound that follows startles all three people in the room, and Benjamin is further startled when the two adults begin emitting sharp, loud sounds toward one another, quite unlike the soft, pleasant sounds they had been producing before. When Benjamin begins crying in response, the adults rush to him, patting him and making soft, especially pleasant sounds to him.

This example, to which we will return throughout the chapter, illustrates the enormous amount of information that is available for an infant to observe and learn from in even the most everyday situations. In learning about the world, Benjamin, like most infants, avidly explores everything and everyone around him, using every tool he has: he gathers information by looking and listening, as well as by tasting, smelling, and touching. His explorations will gradually expand as he becomes capable first of reaching for objects and then of manipulating them, making it possible for him to discover more about them. When he starts to move around under his own power, even more of the world will become available to him, including things his parents would prefer that he not investigate, such as electrical outlets and kitty litter. Never will Benjamin explore so voraciously or learn so rapidly as in the first few years of his young life.

Like Benjamin, this infant will take in a great deal of perceptual information just observing his father washing dishes.

MONALYN GRACIA/CORBIS

In this chapter, we discuss development in four closely related areas: perception, action, learning, and cognition. Our discussion focuses primarily on infancy. One reason for concentrating on this period is that extremely rapid change occurs in all four areas during the first two years of a child's life. A second reason is the fact that infant development in these four domains is particularly intertwined: the minirevolutions that transform infants' behavior and experience in one domain lead to minirevolutions in others. For example, the dramatic improvements in visual abilities that occur in their first few months enable infants to see more of the people and objects around them, thereby greatly increasing the opportunities they have to learn new information.

A third reason for concentrating on infancy in this chapter is the fact that the majority of recent research on perceptual and motor development has been done with infants and young children. There is also a large body of fascinating research on learning and cognition in the first few years. We will review some of this research here and cover subsequent development in these areas in later chapters. A final reason for focusing on infants in this chapter is that the methods used to investigate infants' development in these four domains are, of necessity, quite different from those that researchers are able to use to study older children.

Our examination of key developments in infancy will feature several enduring themes. The active child theme is vividly embodied by infants' eager exploration of their environment. Continuity/discontinuity arises repeatedly in research that addresses the relation between behavior in infancy and subsequent development. In some sections, the mechanisms of change theme is also prominent, as we explore the role that variability and selection play in infants' development. In our discussion of early motor development, we will examine contributions made by the sociocultural context.

Underlying much of this chapter, of course, is the theme of nature and nurture. For at least 2,000 years, an often–contentious debate has existed between those philosophers and scientists who have emphasized innate knowledge in accounting for human development and those who have emphasized learning (Spelke & Newport, 1998). The desire to shed light on this age–old debate is one reason that an enormous amount of research has been conducted with infants over the past few decades. As you will see, these discoveries have revealed that infant development is even more complicated and remarkable than previously suspected.