Achievements of the First Year

The Development of Children (5th ed.)

Cole, Cole & Lightfoot

Chapter 5

Overview of the Journey

Biological changes Perceptual-motor

development Cognitive changes Relationship with the

social world A new bio-social-

behavioral shift

Biological changes Perceptual-motor

development Cognitive changes Relationship with the

social world A new bio-social-

behavioral shift

Biological Changes

Size and Shape

Bone and Muscle

The Brain

Size and Shape Triple in weight…

(7 21 lbs.) Add 10 inches height…

(20 30 in.) Change in body

proportions… At birth, head is 70% of adult

size and accounts for 25% total body length

Legs at birth are not much longer than their heads; by adulthood, legs account for about half of total height

Result in lowering the center of gravity (balance, walking)

Environmental Conditions Influence Growth Rate

Babies born in Malawi face conditions such as widespread mal-nutrition, chronic poverty, disease, and a rising HIV/AIDS infection rate. As a result of this complicated array of factors, Malawian infants grow at a slower rate than their American counterparts.

Babies born in Malawi face conditions such as widespread mal-nutrition, chronic poverty, disease, and a rising HIV/AIDS infection rate. As a result of this complicated array of factors, Malawian infants grow at a slower rate than their American counterparts.

Changes in Body Proportions

Bone, Muscle, & Gender

Bone ossification First in hand and wrist (pick up)

Increases in muscle mass Associated with ability to

stand alone and walk Sex differences

Females are ahead 3 weeks prenatal, 6 weeks at birth, 2 years at puberty

Girls get their permanent teeth, start puberty, and reach full size earlier than boys

Brain Development

Exuberant synaptogenesis (3-12 months) Density of synapses is double what it will be in

early adolescence As a result of this overproduction of synapses,

infants are prepared to establish neural connections for virtually any kind of experience

“Synapses that are regularly used flourish and are strengthened, while those that go unused are gradually ‘pruned away’—that is, they atrophy and die off.” (p. 183)

What might be some educational implications?

Brain Development

2½ - 4 months: Surge in visual cortex 6 months: Spurt in motor cortex 7 - 9 months: Rapid growth

of frontal cortex (used inintegrating information) Prefrontal area plays

a particularly important role in the development of voluntary behavior (e.g., impulse inhibition)

Perceptual-Motor Development

Reaching and Grasping

Locomotion

Reaching and Grasping

Newborns: Perceive an object moving before them and reach for it (i.e., visually initiated reaching)

2 ½ months: Coordination of reach and grasp

5 months: No longer reach for an object beyond their grasp

9 months: Guide movements with a single glance

Fine Motor Movements

Babies seem to perceive that different objects offer different affordances – properties that lend themselves to particular ways of interacting with them

Perceptual-Motor Exploration

Contour following(exact shape)

Pressure(hardness)

Enclosure(volume/size)

Unsupported holding(weight)

Static contact(temperature)

Lateral motion(texture)

Development of Locomotion Development of Locomotion

The integration of movements of many parts of the body

Creep by making pushing movements with knees & toes

1st Month1st Month

Head held up, but leg movements diminish

2nd Month2nd Month

Control over movement of head and shoulders increases

Ability to support upper body with arms improves

Midsection raised, but head lowers

Midsection and head raised, but tend to rock back and forth

Coordinated arm and leg movements enable crawling

7th – 8th Month7th – 8th Month

Walks at around 12 monthsWalks at around 12 months

The Role of Practice

During the 1930s and 1940s it was commonly believed that learning and experience played little or no role in the development of such motor milestones as sitting and walking.

Recent findings: Motor development can be speeded up by extensive practice or slowed when adults seek to protect the child against danger, depending upon the cultural circumstances.

Cognitive Changes

Piaget’s Constructivist Explanation

Are Infants Precocious? Challenges to Piaget’s Theory

Categorizing

Growth of Memory

Piaget: Sensorimotor Stage (Infancy)

Sub Age (M) Description

1 0 – 1 ½ Reflex schemas exercised

2 1 ½ – 4 Primary circular reactions

3 4 – 8 Secondary circular reactions

4 8 – 12 Coordination of secondary circular reactions

5 12 – 18 Tertiary circular reactions

6 18 – 24 Beginning of symbolic representation

Piaget: Sensorimotor Stage (Infancy)

Sub Age (M) Description

1 0 – 1 ½ Reflex schemas exercised: Involuntary rooting, sucking, grasping, looking

2 1 ½ – 4 Primary circular reactions: Repetition of personal actions that in themselves are pleasurable (e.g., blowing bubbles)

Piaget: Sensorimotor Stage (Infancy)

Sub Age (M) Description

3 4 – 8 Secondary circular reactions: Dawning awareness of the effects of one’s own accidental actions on environment, and that extended actions can produce interesting change in the environment

4 8 – 12 Coordination of secondary circular reactions: Combining schemas to achieve a desired effect (inten-tionality; early problem solving)

Object Permanence

Understanding that objects Have substance Maintain their identify when they

change location Continue to exist (ordinarily) when

out of sight – otherwise, “out of sight is out of mind”

An early indicator of the development of representation

For example, an infant younger than 8 months of age does not search for an object that has been removed from sight

For example, an infant younger than 8 months of age does not search for an object that has been removed from sight

Lack of Representation

Infant does not track the movement of the train in the tunnel, is happy to see the train again, but is not surprised that it is now a different color or shape.

Infant does not track the movement of the train in the tunnel, is happy to see the train again, but is not surprised that it is now a different color or shape.

Incomplete Object Permanence (8-12 months of age)

After an infant has successfully searched for an object hidden one location, the object is then hidden in a new location while the infant watches.

The infant will search for the object where it was previously found.

Developments in Object Permanence

1. Infant does not search for objects that have been removed from sight.

2. Infant orients to place where objects have been removed from sight.

3. Infant will reach for a partially hidden object but stops if it disappears.

4. Infant will search for a completely hidden object; keeps searching the original location of the object even if it is moved to another location in full view of the infant.

5. Infant will search for an object after seeing it moved but not if it is moved in secret.

6. Infant will search for a hidden object, certain that it exists somewhere.

Precocious Infants?

Infants 3½ months old dishabituated (i.e., surprised, looked longer) when screen appeared to pass through the place where box had been located

Seemed to indicate reasoning about an impossible event

Baillargeon et al., 1987

Challenges to Piaget’s Theory…

Reversing the Experiment

Cohen et al., 2000

However, when habituated to the impossible event first and then tested on the possible event, the babies stared more than twice as long at this possible event!

In essence, they looked longer at the novel events, whether possible or impossible.

Intermodel Perception Infants held two rings, one in each hand,

under a cloth that prevented them from seeing the rings or their own bodies.

For some infants the rings were connected by a rigid bar and therefore moved together. For others the rings were connected by a flexible cord and therefore moved independently.

All the infants were allowed to hold and feel just one or the other type of rings until they had largely lost interest (habituated).

They were then shown both types of rings.

The babies looked longer at the rings that were different from those they had been exploring with their hands.

Streri & Spelke, 1988

Infant Arithmetic?

Infants (4 months) looked longer at the end display when there was only one doll, suggesting that they had mentally calculated the

number of dolls that ought to be behind the screen. [Wynn, 1992]

Rational Behavior

In this experiment, infants were shown a small circle repeatedly jumping over a barrier to get to another circle (a). After they had habituated to this event, the obstacle was removed. In subsequent tests, the infants looked longer if the circle repeated its familiar jumping action (b) (which was not a reasonable behavior since the barrier was no longer there) than if it took a novel, but more efficient, straight-line route (c).

In this experiment, infants were shown a small circle repeatedly jumping over a barrier to get to another circle (a). After they had habituated to this event, the obstacle was removed. In subsequent tests, the infants looked longer if the circle repeated its familiar jumping action (b) (which was not a reasonable behavior since the barrier was no longer there) than if it took a novel, but more efficient, straight-line route (c).

Infant Categorizing Infants (3 months) shown a

sequence of pictures of cats were surprised when they saw a picture of a dog, suggesting that they were sensitive to the category of cats

Similarly, 3- to 4-month-olds, after having been shown a series of pictures of mammals, looked longer at pictures of non-mammals and furniture than at a picture of a new mammal Eimas & Quinn, 1994

Behl-Chadha et al., 1995

Infant Categorizing After three 15-minute

sessions, each with a different-color A block, a 3-month-old baby will kick the mobile with yet a fourth color added.

But if a new shape is inscribed on the blocks used in the fourth session (e.g., B’s), the baby will not kick, indicating that the baby has formed a category and remembered prior experience

Conceptual Categories

Babies (7 months) treated plastic toy birds and airplanes, which are perceptually similar, as if they were members of the same category

Babies (9 -11 months) treated toy airplanes and birds as members of conceptually different categories, despite the fact that they looked very much alike

Mandler & McDonough, 1993

Growth of Memory

Growth of MemoryIn one study (Rovee-Collier et al.), a group of 3-month-old babies were trained to activate a mobile by kicking. They then let an entire month elapse before putting the babies into the experimental situation again. They knew that this was more than enough time for the babies to forget their training.

However, 1 day before being retested, the 3-month-olds were shown the mobile as a reminder (without allowing them to kick). The next day, these infants started kicking as soon as the ribbon was tied to one of their legs. The mere sight of the mobile a day earlier seemed to remind the babies of what they had learned 1 month earlier.

What might be the educational implications?

Relationship with the Social World

Imitation

Wariness

New Relationships

Deferred Imitation (Evidence of Recall) Infants move from relying

on implicit memory (recognition) to explicit memory (recall)

For example, infants will imitate live models, as well as actions that they have seen on television Infants who watch a televised

model on one day will reproduce the model’s behavior 24 hours later (Meltzoff, 1988)

What might be an educational implication?

Wariness (begins at 6-9 months)

Infants who are exposed to something new – even a spoonful of cereal from a stranger – display characteristic wariness

Another evidence of recall

Indicators of New Social Relationships

Zone of Proximal Development (Vygotsky) Assistance provided by adults goes just slightly beyond the child’s

current competence; helps child learn new behaviors Attachment

Seek to be near their primary caregivers and show distress when they are separated, happy when reunited

Secondary Intersubjectivity Primary: face-to-face

communication (e.g., social smiling)

Secondary: shared communication that refers to objects beyond themselves (e.g., looks when mother points)

Indicators of New Social Relationships

Social Referencing Tendency to look to the caregiver for an

indication of how one should feel and act (girls will do this more than boys)

Language Development Comprehension: understands words for

highly familiar objects (6 months); identifies phrases (8-9 months)

Babbling: Vocalizing that includes consonant/vowel repetitions (7 months)

Jargoning: Babbling with stress and intonation of actual utterances (12 months)

A New Bio-Social-Behavioral Shift

7-9 Months7-9 Months

Prominent Shifts & Periods

Shift Point Developmental Period

Conception Prenatal period

Birth Early infancy

2½ months Middle infancy

7-9 months Late infancy

24-30 months Early childhood

5-7 years Middle childhood

11-12 years Adolescence

19-21 years Adulthood

Characteristics of the Shift

Biological Growth of muscles and hardening of bones Myelination of motor neurons to lower trunk, legs, hands Myelination of cerebellum, hippocampus, frontal lobes New form of EEG activity in cortex

Social Wariness of strangers New emotional response to caregiver (attachment) Secondary intersubjectivity Social referencing

Behavioral Onset of crawling Fear of heights Coordinated reaching and grasping Object permanence displayed in actions Recall memory Babbling and jargoning