Infancy and Toddlerhood

Body Growth Basics

  • height nearly doubles in the first two years of life, and weight quadruples

  • ‘baby fat’ increases over the first year (temperature regulation) then decreases

    • weight unlikely to be concern

    • malnutrition: marasmus, kwashiorkor

    • breastfeeding

  • growth in two patterns

    • cephalocaudal- head to tail

    • proximodistal- near to far

Motor Development

  • gross and fine motor skills

  • dynamic systems theory: motor skills develop based on multiple factors

    • CNS development

    • capacity for movement

    • goals

    • environmental supports

Brain Development

  • the brain more than doubles in size in the first year of life

  • growth - new neurons, fibers, and synapses

    • this requires stimulation - sensitive periods

    • experience- expectant (vs. experience-dependent, which happens through life)

  • programmed cell death- neurons die off to make room for more connections

  • myelination- glial cells coat fibers to speed up transmission

    • huge amount near age 2 (then again at adolescence)

    • why these times?

Cerebral Cortex

  • main area for postnatal brain development

    • prefrontal cortex is the last to fully develop- really develops from about 2 months on

  • lateralization

    • right brain/left brain?

    • depends on experience, stimulation

    • plasticity

Perception

  • habituation

  • vision

    • very poor for newborns

    • depth perception (visual cliff)

    • patterns and faces

    • preferences - sex, race

  • hearing

    • begin developing musical preferences

    • understand where musical phrases (and words!) begin and end

Differentiation Theory

  • infants seek stable features in a changing world

  • then begin to identify patterns and relationships (amodal at first, then intermodal), finer and finer details

  • always looking for possibilities for action

  • may begin imposing meaning- what we call the beginning of cognition

Learning

  • behaviorism research (mind as black box)

  • conditioning

    • classical conditioning

    • operant conditioning

  • social learning

    • modeling, learning by observation

    • developed into social-cognitive theory

“Little Scientists”

  • piaget’s sensorimotor stage - learning by doing

    • begins by reflex and circular reactions and develops into goal-directed behavior

  • we develop schemas about how the world works, and constantly update them

    • accommodation - updating our schemas to match the world

    • then using them to interpret: assimilation

    • organization- connecting various schemas together

  • mental representations help us think about things when they’re not there

    • deferred imitation, make-believe

  • general ideas have stayed useful - however, piaget’s timelines may not be accurate

    • more continuous- object permanence may be a matter of degree, for example

Information Processing Approach

  • ‘mind as a computer’ analogy

  • how do each of these change during the first two years of life?

  • more sustained attention

  • greater memory retention and retrieval

    • recognition - recall is more difficult

  • if that’s the case, why dont we remember this part of our life?

Infantile Amnesia

  • possible explanations

    • language

    • schemas

    • brain development

Language Development Theories

  • is language taught or are we naturally oriented toward developing it?

  • chomsky’s language acquisition device, sensitive period

  • interactionist perspectives

    • information processing - same general cognitive capacities as for understanding other patterns, music, art, etc.

    • social interactions - language develops out of social interactions and is driven by those relationships (Vygotsky)

  • role of adults, environment

    • infant-directed speech

Attachment

  • ethiological theory; internal working model

  • if secure bond formed, will feel more confident to explore

    • secure base, stranger anxiety

  • if insecure, emotional difficulties may follow (specific to type of insecurity)

    • avoidance, anxiety, disorganization

  • fairly stable and predictive of later relationships/outcomes, but can be changes (especially if insecure)

  • erikson’s stage of trust vs distrust (infancy)

Factors Affecting Attachment

  • early availability of consistent caregiver

  • quality of caregiving

  • infant characteristics (including genetics - another gene x environment interaction)

  • parent’s own attachments

  • other factors - SES, culture

Emotion

  • ekman: 6 basic emotions

    • for infants, we see basic attraction/ withdrawal that gets more complex

  • happiness, surprise

    • social smiles, laughter

  • anger, sadness, fear

    • increase with autonomy, especially anger

    • stranger anxiety and the secure base

  • responding to others’ emotions

  • self-conscious emotions (pride, guilt, embarrassment) emerge around 1.5

Temperament

  • basic personality

  • seems to be partially genetic but is also affected by environment

    • gene x environment interactions - parenting style more important for children with low proprensity for emotion regulation

      • goodness of fit model

  • classic 3 types

    • ‘easy’, ‘difficult’, and ‘slow to warm up’

    • however this only described about 2/3 of their sample and may be stigmatizing in terms of language

  • modern conceptions have more components

    • activity level, attention span, fearful distress, irritable distress, positive affect, effortful control

Self Development

  • early self-awareness demonstrated by distinguishing self/body from others

  • self recognition in mirror around 1.5 years

    • culture-dependent- why?

  • scale errors (e.g., doll’s clothes)

  • development of empathy

    • broccoli

  • self-control and delayed gratification

    • marshmallow test (role of SES)