Key Terms and Concepts
lateralization myelin nightmare night terror obesity child abuse cycle-of-violence hypothesis psychological maltreatment child neglect resilience handedness
Brochure Outline Physical Growth: Children’s physical growth during the preschool period proceeds steadily. Differences in height and weight reflect individual differences, gender, and economic status. In addition to gaining height and weight, the body of the preschooler undergoes changes in shape and structure. Children grow more slender, and their bones and muscles strengthen.
Children’s bodies continue to grow during the preschool period.
1. Average 6-year-old weighs 46 pounds and is 46 inches tall.
2. There are significant individual differences in height and weight. a. 10 percent of 6-year-olds weigh 55 pounds or more, 10 percent weigh
36 pounds or less. b. By the age of 6, boys are taller and heavier, on average, than girls.
3. There are profound differences in height and weight between children in economically developed countries, who tend to be taller and heavier, and those in developing countries.
4. Differences in height and weight also reflect economic factors within the U.S.
Changes in body shape and structure occur during the preschool years.
1. Boys and girls become less chubby and roundish and more slender.
2. Arms and legs lengthen.
3. By age 6, body proportions are more similar to those of adults.
4. Children grow stronger as muscle size increases and bones become sturdier.
5. The sense organs continue to develop.
The Growing Brain
1. Brain growth is particularly rapid during the preschool years, with the number of interconnections among cells and the amount of myelin around neurons increasing greatly.
2. Through the process of lateralization, the two halves of the brain begin to specialize in somewhat different functions. However, despite lateralization, the two hemispheres function as a unit and in fact differ only slightly.
a. The left hemisphere focuses on verbal competence (speaking, thinking), and considers information sequentially.
b. The right hemisphere concentrates on nonverbal areas (spatial relations, music, emotional expression), and considers information more globally.
c. The two hemispheres of the brain act in tandem.
3. There are many individual differences in the nature of lateralization, and in relation to gender and culture.
a. Males show greater lateralization of language in the left hemisphere, whereas for females, language is more evenly divided between the two hemispheres. (This may account for why female’s language development proceeds at a more rapid rate during early childhood.)
b. The differences in lateralization between males and females may be attributed to both genetic and environmental factors.
(1) The corpus callosum, a bundle of nerve fibers that connects the hemispheres of the brain, is proportionately larger in women than in men.
(2) Girls receive greater encouragement for verbal skills than boys
4. There is some evidence that the structure of the brain differs by gender and culture. For instance, boys and girls show some hemispheric differences in lower body reflexes, the processing of auditory information, and language. Furthermore, some studies suggest that such structural features as the processing of vowel sounds may show cultural differences.
5. The brain is remarkably resilient: when one hemisphere is damaged, the other hemisphere can compensate.
6. Neuroscientists are just beginning to understand the ways in which brain development is related to cognitive development.
a. Increases in myelin, the protective insulation that surrounds parts of the neuron, may be related to preschooler’s growing cognitive capabilities.
b. Increased myelin may be associated with improvements in attention, concentration, and memory as children approach school age.
The increasing development of the brain permits improvements