Discussion: A Changing Body and Brain

For more than a decade, my fourth-floor office window overlooked the preschool and kindergarten play yard of our university laboratory school. On mild fall and spring mornings, the doors of the classrooms swung open, and sand table, easels, and large blocks spilled out into a small courtyard. Alongside the building was a grassy area with jungle gyms, swings, a playhouse, and a flower garden planted by the children. Beyond it lay a circular path lined with tricycles and wagons. Each day, the setting was alive with activity.

The years from 2 to 6 are often called “the play years,” since play blossoms during this time and supports every aspect of development. Our discussion opens with the physical attainments of early childhood—growth in body size and improvements in motor coordination. We look at genetic and environmental factors that support these changes and at their intimate connection with other domains of development.

Then we explore early childhood cognition, beginning with Piaget’s preoperational stage. Recent research, along with Vygotsky’s sociocultural theory and information processing, extends our understanding of preschoolers’ cognitive competencies. Next, we address factors that contribute to early childhood mental development—the home environment, the quality of preschool and child care, and the many hours young children spend watching television and using computers. We conclude with the dramatic expansion of language in early childhood.

PHYSICAL DEVELOPMENT

A Changing Body and Brain

In early childhood, body growth tapers off from the rapid rate of the first two years. On average, children add 2 to 3 inches in height and about 5 pounds in weight each year. Boys continue to be slightly larger than girls. As “baby fat” drops off further, children gradually become thinner, although girls retain somewhat more body fat than boys, who are slightly more muscular. As Figure 7.1 shows, by age 5 the top-heavy, bowlegged, potbellied toddler has become a more streamlined, flat-tummied, longer-legged child with body proportions similar to those of adults. Consequently, posture and balance improve—changes that support gains in motor coordination.

Individual differences in body size are even more apparent during early childhood than in infancy and toddlerhood. Speeding around the bike path in the play yard, 5-year-old Darryl—at 48 inches tall and 55 pounds—towered over his kindergarten classmates. (The average North American 5-year-old boy is 43 inches tall and weighs 42 pounds.) Priti, an Asian-Indian child, was unusually small because of genetic factors linked to her cultural ancestry. Hal, a Caucasian child from a poverty-stricken home, was well below average for reasons we will discuss shortly. Discussion: A Changing Body and Brain

Discussion: A Changing Body and Brain