Chapter 7Development Across the Lifespan The Preschool Years: Physical and Cognitive Development
What’s going on to effect development during the preschool years (ages 3 thru 6)? • Preschool! • The start of intellectual and social interaction • Practice/preparation for child’s formal education * TREMENDOUS growth and change during this period! • physical • (weight, height, nutrition, health, physical brain changes, motor skills) • Cognitive • (intellectual development, language)
Physical Growth…The Growing Body • Preschool age children’s physical abilities advance significantly (compared to infancy stage) • Children grow steadily during the preschool period
Physical Development: Gaining Height & Weight The figures show the median point for boys & girls at each age (50% of children above this point, 50% below)
These averages mask individual differences in height & weight • By the age of 6, boys are taller and heavier, on average, than girls. • There are profound differences in height and weight between children in economically developed countries and those in developing countries. WHY? • Nutrition, healthcare • Differences in height and weight also reflect economic factors within the U.S. • Children whose families are below the poverty level are among the shortest of all preschool age children
Changes in body shape and structure occur during the preschool years • Boys and girls become less chubby and roundish and more slender (no more potbelly!). • Arms and legs lengthen. • Children grow stronger as muscle size increases and bones become sturdier. • The sense organs continue to develop. • Body proportions are more similar to those of adults (relationship between head and body more adultlike).
Nutritional needs change during the preschool years (& effect development!). • The growth rate slows during this age, thus preschoolers need less food to maintain their growth. • Encouraging children to eat more than they want to, may lead to increased food intake.
(Nutrition during the preschool years, continued) Increased food intake may lead to OBESITY, (defined as a body weight more than 20 % higher than the average weight for a person of a given age and height; • Obesity is more common among older preschoolers than it was 20 years ago • Obesity is brought about by both biological (genetics, responsiveness to sweets) and social factors (parental encouragement).
It is important not to force children to eat too much in the mistaken belief that they need more food! • Children tend to be quite adept at maintaining an appropriate intake of food. • The best strategy is to ensure a variety of foods, low in fat and high in nutritional content. • Children should be given the opportunity to develop their own natural preferences for foods (no one food is indispensable!)
Health & Illness during the preschool years • The majority of children in the United States are reasonably healthy. • For the average American child, the common cold is the most frequent, and most severe, illness. • The proportion of children immunized in the U.S. has fallen during some portions of the last two decades.
Recommended immunization schedule (American Assn. Of Pediatrics). In text…
Although physical illness is typically a minor problem during the preschool years, more children are being treated for emotional disorders • The use of drugs such as antidepressants and stimulants doubled and tripled between 1991 and 1995 • Reason for increase is unclear • Quick fix for behavioral problems & normal developmental difficulties? ~Therapy is beginning to replace drugs as the treatment of choice!
Numbers of Preschool Children Taking Medication for Behavioral Problems
Injuries: The Dangers that Preschoolers Face The danger of injuries during the preschool years is in part a result of children's high levels of physical activity (they can get around on their own now!). • Poison, drowning in tub/pools, falls, burns Some children are more apt to take risks than others, leading to more injury • Boys have higher injury rates. Economic and ethnic differences exist in injury rates. • Living in poverty environment = 2x higher risk • Cultural differences in supervision, gender roles
The Consequences of Lead Poisoning High levels of lead have been linked to higher levels of antisocial behavior, including aggression & delinquency in school-age children.
Another factor effecting development during the preschool years: Brain Growth The brain grows at a faster rate than any other part of the body! • By age 5, children's brains weigh 90 % of average adult brain weight. • Brain growth is so rapid because of the increase in the number of interconnections among cells, and the increase in myelin (the protective insulation that surrounds parts of neurons).
The 2 halves of the brain begin to become more differentiated and specialized • The left hemisphere focuses on verbal competence (speaking, thinking), and considers information sequentially (focus on parts). • The right hemisphere concentrates on nonverbal areas (spatial relations, music, emotional expression), and considers information more globally (focus on wholes).
(Brain lateralization continued) • The two hemispheres of the brain act in tandem (work together) despite specialization of hemispheres (they are interdependent, not independent) • This specialization is studied using MRI’s and the lateralization pattern is true for most people
Looking Into the Brain… These scans show how different parts of the brain are activated during certain tasks, illustrating the increasing specialization of the brain.
(Brain lateralization continued) • There are many individual differences in the nature of lateralization, and in relation to gender and culture. • 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.)
(Brain lateralization continued) • The differences in lateralization between males and females may be attributed to both genetic (corpus callosum differences—larger in women) and environmental factors (girls typically receive greater verbal encouragement). (nature vs. nurture again!)
Links Between Brain Growth & Cognitive Development… • Neuroscientists are just beginning to understand how brain development effects cognitive development. • It seems that there are periods of childhood during which the brain shows unusual growth spurts which have been linked to advances in cognitive ability. • Spurts at age 1 ½ to 2 years of age: linked to language increases
Brain Growth Spurt Graph shows that brain activity increases drastically during 1 ½-2 years of age when language dramatically increases
Motor Development in the Preschool Years (ages 3—6) • Both gross and fine motor skills become increasingly fine-tuned during this age. • Preschoolers' level of activity is extraordinarily high. • According to research, the activity level at age 3 is higher than at any other point in the lifespan! • (Eaton & Yu, 1989; Poest et al. 1990)
(Motor Development in the Preschool Years continued) Girls and boys differ in certain aspects of motor development. • Boys, because of increased muscle strength, tend to be somewhat stronger. • Girls tend to surpass boys in tasks of dexterity or those involving the coordination of limbs.
Some major gross motor skills in early childhood • Hopping • Skipping • Running • Throwing (see table ; emphasizes how gross motor skills improve with time)
Fine Motor Skills are also developing during this period • Using utensils to eat • Cutting things with scissors • Tying shoelaces • Drawing shapes • Puzzles • Require much more practice than gross motor skills!
A final component of motor development: Handedness • Preference begins in infancy, but more finalized in the preschool years • Most preschool children show a clear preference for the use of one hand over another - the development of HANDEDNESS.
(Handedness Continued) • 90 % of preschoolers are right-handed • more boys than girls are left-handed (so there IS a gender difference) • There is no scientific basis for myths that suggest there is something wrong with being left-handed.
Intellectual Development In the Preschool Years • How do the dramatic advances in intellectual development that begin during the preschool years take place? • We will consider several different explanations…
Cognitive Changes that occur during the preschool years: Intellectual Development • Piaget's Stage of Preoperational Thinking • Piaget saw the preschool years as a time of both stability and great change. • Preschoolers are in the PREOPERATIONAL STAGE, from age 2 to 7 • characterized by symbolic thinking • Mental reasoning emerges, use of concepts • Less dependence on sensorimotor activity for understanding the world
(Piaget's Stage of Preoperational Thinking continued) • A key aspect of preoperational thought is symbolic function ( the ability to use symbols, words, or an object to represent something that is not physically present). • Using word duck as a symbol for an actual duck • Understanding that a toy duck represents an actual duck • Symbolic function is directly related to language acquisition.
The relationship between language and thought • For Piaget, language and thinking are interdependent (advances in language during the preschool period = advances in thinking) • Language allows preschoolers to represent actions symbolically. • Language allows children to think beyond the present to the future. • Language can be used to consider several possibilities at the same time
Do improved language abilities in preschoolers lead to improvements in thinking ability, or is it the reverse? A controversial question in the field of psychology! • Addressing the question if thought determines language or if language determines thought, Piaget argued that language grows out of cognitive advances (more sophisticated thinking patterns)
) Another aspect of intellectual development during the preoperational period (according to Piaget): C ENTRATION - the process of concentrating on one limited aspect of a stimulus and ignoring other aspects (buttons) • a major characteristic of preoperational thought • the major limitation of this period because it leads to inaccuracy of thought. • The cause of the children’s mistake is allowing the visual image to dominate their thinking (appearance is everything!)
Centration: What You See is What You Think Which row contains more buttons? Preschoolers usually say that the bottom row has more because it looks longer. (an example of conservation of number, which we will discuss)
Another aspect of intellectual development during Piaget’s preoperational period… Egocentrism, the inability to take the perspective of others • EGOCENTRIC THOUGHT, thinking that does not take into account the viewpoint of others, takes two forms: 1) Lack of awareness that others see things from different physical perspectives. • Failure to realize that others may hold thoughts, feelings, and points-of-view different from one's own.
(EGOCENTRIC THOUGHT, continued) • Not intentional/inconsiderate—just lack of understanding that everyone doesn’t view things like them! • Egocentrism is at the root of many preschool behaviors, for example, talking to oneself and hiding games (if I can’t see you, then you must not be able to see me!).
More about intellectual development during Piaget’s preoperational period • Preschoolers are unable to understand the notion of TRANSFORMATION ( the process in which one state is changed into another - because they ignore the intermediate steps [ inability to understand/fill in sequences of change] ) • Pencil; slugs crawling
The Falling Pencil & Transformation Children in the preoperational period are not able to understand the successive transformations that the pencil follows. They cannot see the intermediary steps.
A number of advances in thought occur in the preoperational stage. 1) INTUITIVE THOUGHT – (ages 4-7) the use of primitive reasoning and avid acquisition of knowledge about the world; simply put: CURIOSITY • Leads children to think they know all the answers for how the world operates, but no logical basis yet
(advances in thought occur in the preoperational stage, continued) • Children begin to understand functionality - the concept that actions, events and outcomes are related to one another in fixed patterns. • Pushing pedals moves bike faster, remote button changes channels on TV
(advances in thought occur in the preoperational stage, continued) • They begin to understand the concept of identity - that certain things stay the same regardless of changes in shape, size and appearance • Clay stretched out is the same amount of clay rolled into a ball According to Piaget, understanding identity necessary for children to develop an understanding of conservation (which is required for the child to transition to the next stage in his theory)
Conservation: Learning that Appearances are Deceiving • Preschoolers do not understand CONSERVATION - the knowledge that quantity is unrelated to the arrangement and physical appearance of objects
Number Rearranging elements The type of conservation task grasped the earliest! Substance Altering shape (clay, water) Length Altering shape, configuration Area Rearranging figures Weight Altering shape Volume Altering shape (water in container) Types of Conservation Problems