Lecture 4 - Motor development

PSYC205 Week 2: Lecture 4 - Motor Development

Understand the stage view of motor development
Grasp the basic tenets of dynamic systems theory in motor development
Explore links between motor and social development within the broader context of developmental processes

Stage View (Descriptive viewpoint: What)
- Biological changes enable behavioral changes
- Motor behaviors are sequenced and ranked
- Correlation between mean age of skill attainment and specific motor skills
- Evidence of similar developmental milestones across cultures (Ulrich, 1991)
Process View (Explanatory viewpoint: How)
- Focuses on real-time adaptations and interactions

Characteristics:
- Progresses from simple to complex
- Sequential and orderly
- Builds upon fundamental skills
- Not all infants follow the same path (e.g., 20% skip crawling)
Developmental Milestones:
- Cephalo-Caudal Development: Control from head to tail
  (e.g., lift head → sit → walk)
- Proximal-Distal Development: Control from central to
  peripheral
- control of shoulders before wrists before fingers
  (e.g., bat at object → directed reach → grasp)

Developmental charts are reliable for assessing early childhood development
No significant changes were observed between the 1970s and 2018 for 0-36 month-olds
Importance of cultural sensitivity in defining normative development

Focuses on the "how" rather than the "what"
Maturation systems are the foundation
Skills are reorganizations of existing abilities
Movement is soft-assembled and emergent
Reorganisation occurs as new and more effective ways of exploring are sought
Interaction between individual, environment, experience, and maturation leads to affordances or constraints
There is an interaction between biological changes and experiences

Stage View: Development of motor cortex and motor program
Dynamic Systems View: All systems (emotional, motivational, anatomical) must be ready

Onset of Locomotion:
- Onset of crawling creates new challenges for infants and parents
- Encourages exploration and autonomy
- Dramatic changes in social signals received and initiated by infants
- Discourage and prohibit
- '‘psychological birth of the infant human”
Changes in Family Dynamics:
- Tug of war between infant willfulness and parental compliance
- New forms of affection emerge like peek a boo games
Changes in the Infant:
- Increased affection towards primary caregivers
- Greater sensitivity to maternal presence and maternal location
- Onset of temper tantrums and social referencing
- Increased attendance to distal events, parts of the environment/object not immediately near by
Changes in the Parent:
- Expectation of compliance from infants, feel that infants are now responsible for their actions
- Increased verbal prohibitions and expressions of anger
- Using distaction to move infants from potential dangerous sitations
- New affectionate behaviour including more hugs/cuddles

New attachment behaviours emerge, such as proximity-seeking
Carrying objects; approach caregivers to share joint attention or initiate information seeking
Infants who engage in joint attention are more likely to walk earlier

Organized exploration sequence influences visual and haptic behaviors
Visual exploration prompted gait modifications and hapctic explorations
Milestones in motor development correlate with language development (e.g., sitting → babbling)
- ability to sit with support -> produce consonant like sounds at 20 weeks
- ability to sit independently -> first production of babbling at around 6 months through exploration of own vocal tract
- self locomotion -> first word
Early walkers are usually early talkers: have greater opportunity to explore the environment, to discover and manipulate new objects and to elicit new words from caregivers as a result (Oudgeneog- Paz et al., 2012, 2013).
Infants’ experience of sitting unaided and exploring objects visually and manually predicted their ability to mentally rotate 3D objects (Sosk

9 -month-old infants’ sustained attention to objects held was predictive of vocabulary at 12 and 15 mo (Yu, Suanda, & Smith, 2019)
Active and efficient manual exploration at 5 mo correlated with academic achievement as late as 14 years of age (Bornstein, Hahn, & Suwalsky, 2013; Muentene, Herrig, & Schuz, 2018)
Fine motor and social interaction skills moderated prosocial understanding and behaviour at 16 mo (Koster et al., 2019)
Motor skills (oral motor control) associated with language production at 21

Embodied: Interaction with physical forces
- Forces act on the body: gravity, friction forces, ground reaction force
- Forces generated by the body: propulsive force and torques
- Novice infant walker with short, irregularly spaced steps and the feet wide apart
- Experienced infant walker with longer, narrower, more regularly spaced steps
Embedded: Influenced by environmental affordances
- Embedded in the perceived affordances of the environment, e.g., a steep slope
- Footprints show characteristic gait modifications in an experienced infant walker while approaching and descending a shallow 6◦ slope and a steep 24◦ slope
Enculturated: Affected by socio-cultural practices
- Footprints show the characteristic walking patterns of an infant (black) and caregiver (blue) during free play
- Can be hindered or facilitated by socio-cultural practices
Enabling: Movement creates new developmental opportunities
- Movement enables new developments
- As average field of view for crawling and walking infants changes, new possibilities arise – unless the infant turns head and looks, dog, train, mother’s face, window, crib is not in view

Chapter 3 of the handbook
Adolph, K. E., & Hoch, J. E. (2019). Motor development: Embodied, embedded, enculturated, and enabling. Annual Review of Psychology, 70, 141-164.
Campos, J. J., et al. (2000). Travel broadens the mind. Infancy, 1(2), 149-219.
Spencer, J. P., et al. (2011). A dynamic systems revolution in motor and cognitive development. Child Development Perspectives, 5(4), 260-266.
Thelen, E. (2000). Motor development as foundation and future of developmental psychology. International Journal of Behavioral Development, 24(4), 385-397.