Milestones in Physical Development from Infancy to Childhood

1. Physical Development • In Utero: • Zygote: conception-2 weeks • Embryo: 2 weeks-2 months (8 weeks) • Cell differentiation • Fetus: 2 months to birth • Functioning organ systems develop, early reflexes seen (e.g. non-nutritive sucking) • Infancy: • Very slow development, comparatively • Brain development takes off: synaptic growth then pruning • Spurts of growth throughout childhood (body and brain)

2. Physical Development • From birth: • Reflexes: • Grasping • Rooting • Foot flexing • Sensory • Discriminate high and low sounds, vowels, mother’s voice • Very near-sighted, but can discriminate brightness and color and track moving objects

3. Physical Development • Gross motor skills • 7-8 months: sitting up • 8-10 months: crawling • 10-12 months: “cruising” • 12-15 months: walking • 2 years: hopping on one foot, kicking • 4 years: jumping rope, balancing on one foot • Fine motor skills • 1 month: reflexive grasp • 4 months: reaching, hands at midline • 6 months: reach precisely, grabs at objects • 12-14 months: throwing objects • 2 years: unscrewing jars • 3 years: cutting with scissors, holding pencil • 6 years: writing, drawing shapes

4. Physical Development • Brain: • Making/pruning connections • Attention • Infants have little selective attention. If something is interesting, they will look at it. • Development of Prefrontal cortex (PFC)development of attentional control • 1-2 years: single-channeled attention: can concentrate on task, but not external verbal/visual stimuli • 2-3 years: still single-channeled, but with help can adjust focus back and forth • 3-4 years: single-channeled, but can adjust focus on their own • 4-5: two-channeled, but short attention span • 5-6: audio, visual, and manipulatory channels integrated

5. Physical Development

6. Physical Development • Brain: • Making/pruning connections • Attention • Infants have little selective attention. If something is interesting, they will look at it. • Development of Prefrontal cortex (PFC)development of attentional control • 1-2 years: single-channeled attention: can concentrate on task, but not external verbal/visual stimuli • 2-3 years: still single-channeled, but with help can adjust focus back and forth • 3-4 years: single-channeled, but can adjust focus on their own • 4-5: two-channeled, but short attention span • 5-6: audio, visual, and manipulatory channels integrated

7. Jean Piaget (1896-1980) • Swiss Psychologist • “Father of Developmental Psychology” • Creator of “constructivist theory of knowing”

8. Stage Theory of Development Sensorimotor Stage • Children progress through a series of stages of development • Long periods of time spent in each stage, abrupt transition to next stage Preoperational Stage Concrete Operations Stage Abstract Operations Stage

9. Sensorimotor Stage • From birth to ~2 years old • Experience the world through senses and motor movements (progress from reflexes to deliberate directed movements) • Schema: mental representation of what things are/how we deal with them • Object Permanence • Internal Representation • Egocentrism

10. Preoperational • 2-7 years of age • Symbolic thought • Egocentrism • Animism • Failure of Conservation

11. Concrete Operational • Ages 7-11 • Logical thinking • Development of rational, “operational” thought • Can think logically about object, if they are able to manipulate it.

12. Formal Operational • 11 and up • Abstract thinking • Can think logically about objects even if not present • Problem solving

13. Arguments against Piaget • Argument 1: Discrete stages do not properly explain child development • A lot of child knowledge is more context-dependant • Argument 2: Young children are actually more advanced than Piaget gave them credit for.

14. Using Habituation in Infants • More boring babies! • Procedure: Show baby image/scene until he/she no longer looks at it. • Test: Introduce new image/scene. • If baby looks longer at new image, it’s perceived as new.

15. Drawbridge Experiment • Child habituated on (A) • Child sees possible outcome (B) and impossible outcome (C) • Child looks more at impossible event than possible event • Child knows block is there, even if he can’t see it

16. Numerical Reasoning Revisited • Number Conservation Task • Children are confused by experimenter’s questions- why is he asking the same question again? • Knowledge still tentative, but there

17. An alternative theory: Information Processing • Human brain as computer • Representation of information • Processes: applied on representations • Limitations: memory • Development = change in processing abilities

18. Rehearsal as Information Processing • Increase in rehearsal speed, increase in memory • Older children actively use rehearsal as a memory strategy and remember more

19. The Sociocultural account • Vygotsky • Cognitive development happens in the context of social interaction • Development happens through internalization of socially shared processes • Zone of Proximal Development