PSY100 Lecture 7: March 5
Part 1: DEVELOPMENT
A) The Developing Body
Progression is predictable.
A genetic component?
But culture can also play a role.
Prenatal period (prior to birth)
Zygote (fertilized egg) starts dividing, doubles, forms a
BLASTOCYST that keeps growing as cells
continue to divide for the first 1.5 weeks or so
2nd-8th week: Embryo (limbs take shape, cells start to
2nd month-birth: Fetus (development after all major organs are
established, physical maturation is the primary
Huge neuron development between 19th day after fertilization
and end of 7th month
Basic brain cells (week 4)
Cortex cells (week 7)
Thalamus/hypothalamus (week 10)
Left/right hemispheres (week 12)
Brain development continues into old age.
Myelinated axons form synapses with more neurons than infant
brain will use.
Synaptic pruning occurs- process where the frequently used
synaptic connections are preserved, those that
aren't are lost.
Embryonic stage is a CRITICAL PERIOD. The embryo is especially
susceptible to TERATOGENS (any agent that
causes a birth defect because it cannot be filtered
out by the placenta)
Drugs, radiation, viruses/bacteria, alcohol (FETAL ALCOHOL
Teratogens can affect size, behaviour, intelligence/reasoning,
health, language, organs, limbs…
Infants are born with an immature visual system (~20/300)
Acuity is at about 20-30 cm.
Can detect movement and large objects
Especially love faces and eyes :)
Experience size constancy
Do not have depth perception
Learns with experience and making connections with monocular
Other senses function from day 1 but still require development
Orient to sounds, especially loud sounds and human speech
First week: recognize mother's smell, like food that mother ate
while pregnant, preference for novel stimuli,
gaze longer at face-like pattern than non
First few weeks infants have REFLEXES: involuntary, unlearned
motor behaviours which go away when the
infants have more control over their motor
Rooting: turning head and opening mouth in direction of touch on
B) Cognitive Development: Piaget
Children also develop increasing sophistication in cognitive
processes like thinking, remembering, and information
These stages are universal and all children go through them in a
set order- each stage is qualitatively different from the
Development of Schemas:
Children are active learners in their environments
Assimilation: taking new info and fitting it into an already-
Accommodation: changing existing schemas or creating new
schemas to fit in new information
Piaget's 4 Periods of Cognitive Development
1) Sensorimotor (Birth-2 years)
Child learns things directly through the senses
Learn that they can act on objects in their environments.
Cannot make mental representations ("out-of-sight-out-of-mind")
9 months- OBJECT PERMANENCE: understand that an object
exists even if it can't ben seen
2) Preoperational Stage (2-7 years)
a child begins to be able to make mental representations due to
advances in symbolic thought
Words, images, and symbols represent world
They can't think operationally- imagine the logical outcome of
performing certain actions on objects
Though they can group things by a concrete element like colour
EGOCENTRIC: cannot take another person's perspective.
Lack understanding of CONSERVATION: the understanding that
important properties of a substance/object
remains constant despite a change in its
3) Concrete Operational Stage (7-11 years)
characterized by the ability to perform mental operations on
physical events only
Children have conservation at this point.
Classification and categorization of concrete objects
Inability to reason abstractly.
i.e. cannot reason about what is possible/understand ideas like
justice or freedom
4) Formal Operations Stage (adolescence-adulthood)
characterized by ability to perform hypothetical reasoning beyond
the here and now, influenced by education
ability to think logically about abstract principles and hypothetical
realistic expectations about future
think about ideals (what do you want to be when you grow up)