The Development of Children, Seventh Edition Cynthia Lightfoot, Michael Cole, and Sheila R. Cole Chapter 5: Physical and Cognitive Development in Infancy

Chapter Overview Physical Growth Brain Development Motor Development Cognitive Development: The Great Debate Conceptual Development The Growth of Attention and Memory Implications

I. Physical Growth During the first year, babies: Triple in weight Grow about 10 inches Changes in body proportions Head to legs ratio Gender differences

Body Proportions

I. Apply – Connect – Discuss Provide some concrete examples of how socioeconomic status may affect infants’ physical growth.

II. Brain Development Increased myelination of neurons Development of prefrontal cortex Growth of language-related areas Increased synchrony among the brain areas

Brain and Behavior As a result, More systematic problem solving Voluntary control of behavior Acquisition of language

Brain and Experience Effects of prolonged deprivation Example: studies of Romanian orphans Effects of lack of experience Experience-expectant Experience-dependent

II. Apply – Connect – Discuss Review the four central issues of developmental science that were discussed in Chapter 1. How does current knowledge of infant brain development shed light on these issues?

III. Motor Development Fine Motor Skills Gross Motor Skills Increased ability to explore environment

Fine Motor Skills Fine Motor Skills: Reaching and grasping Involve the development and coordination of small muscles Reaching and grasping Manual dexterity

Reaching and Grasping

Fine Motor Skills By age 2, feed and dress themselves turn book pages cut paper string beads stack blocks

Gross Motor Skills Gross Motor Skills: Involve the large muscles of the body and make locomotion possible

Progression of Locomotion

Gross Motor Skills Crawling Walking By 8 to 9 months Wariness of heights Walking Cultural variations

Control Elimination Maturation of sensory pathways Cultural Influences From reflex to control Must learn to associate sensory signals with need to eliminate. When to “hold it” Cultural Influences

III. Apply – Connect – Discuss Imagine two children – one an early walker, walking well at 9 months of age, the other a late walker, walking well at 15 months. Suppose both children live in the same neighborhood or village and have parents with similar resources and with similar child-rearing practices and beliefs. Explain how the difference in onset of walking may have significant implications for each child’s development.

IV. Cognitive Development: The Great Debate When does conceptual understanding begins? Piaget’s explanation Other developmentalists’ explanation

Piaget’s Explanation Piaget’s Stage Theory Sensorimotor intelligence at birth Representational thinking begins around 18 months

Piaget’s Stage of Sensorimotor Development Acquisition of knowledge Motor actions Directed at environment Guided by senses

Sensorimotor Substages Substage 3: Secondary Circular Reactions 4 to 8 months Repeating actions that involve objects Substage 4: Coordination of Secondary Circular Reactions 8 to 12 months Displaying intentionality, engaging in goal-directed behavior

Sensorimotor Substages Substage 5: Tertiary Circular Reactions 12 to 18 months Deliberately varying their actions, thus experimenting Substage 6: Beginning of Symbolic Representation 18 to 24 months Basing their actions on representations Important for problem solving, symbolic play, deferred imitation, and the use of language

Sensorimotor Development Cross cultural studies Piaget’s observations have been widely replicated around the world. Challenges -Both to the theory and methods in the past two decades

IV. Apply – Connect – Discuss Imagine that you have been hired by a company to develop a line of toys appropriate to the ongoing sensorimotor development of infants through age 2. Prepare a presentation of some of your ideas for products, including arguments for how your products will appeal to infants at the various substages of sensorimotor development.

V. Conceptual Development Object Permanence The understanding that objects continue to exist when out of sight Two Explanations of Conceptual Development Piaget Alternative Perspective

Alternative Approaches Measuring Object Permanence Violation of Expectations Methods Dynamic Systems Approach Role of Experience

Alternative Research Methods Violation of Expectations Method Habituate babies to a particular event and then present two variants of the event – one that is “possible” under normal circumstances, and one that is “impossible.” Study results Capable of representation as young as 2 ½ months

Alternative Approaches Dynamic Systems Approach Cognitive development in infancy involves not a shift from sensorimotor to conceptual intelligence but growing abilities to coordinate all the various systems involved in sensorimotor and conceptual intelligence.

Alternative Approaches Role of Experience Preference for “novel” objects Preference for “familiar” objects

Understanding Other Properties of the Physical World Initial grasp of various physical laws as young as 3 months Violation of expectations method Example: law of gravity

Reasoning about Objects Challenges to Piaget’s view of cognitive development Counting Cause-Effect Relationships Categorization

Reasoning about Objects: Categorization Changes in categorization abilities Improved perceptual abilities Changes in both perceptual features and conceptual categories

V. Apply – Connect – Discuss Design an experiment to test whether infants understand the difference between “natural” objects (trees, fish, people, etc.), and “artificial” objects (cars, watches, buildings, etc.).

VI. The Growth of Attention and Memory Significance of attention and memory Each plays a role in previously discussed developments Attention Memory

The Process of Attention Four distinct phases: Stimulus-Detection Reflex Stimulus Orienting Sustained Attention Attention Termination Distinguished by changes in heart rate

Attention Processing information takes time Simple vs. complex stimuli Younger children need more time to process Simple vs. complex stimuli

Memory Development of procedural memory Time to forget procedure 2 months: 1-2 days 6 months: 2 weeks Longer if visual reminder Shift from relying on implicit memory to explicit memory

Memory Implicit Memory: Explicit Memory: Recognizing what has been experienced before Explicit Memory: Recalling absent objects and events without a reminder

VI. Apply – Connect – Discuss In what ways might changes in the brain contribute to the development of attention and memory during infancy?

VII. Implications During this brief period, infants undergo enormous physical and cognitive changes with astonishing implications for future development. Brain development Physical development Cognitive development