What is development
Aage related changes that occur as individual progresses from conception to death.
- Predictable sequence.
- Life-history Theory
Prenatal and Childhood development
- Brain development.
- Cognitive Development.
- Moral Development.
- Attachment.
• Development continues through adolescence and adulthood.
Infant brain development
Plasticity: brain’s ability to change structure & function:
- Changes in structure:
• Number of dendrites and connections increases dramatically following birth.
• 2 years: 15,000 synapses/neuron; twice as many as adults.
- Changes in function:
• Newborns: high activity in thalamus.
• Highly dependent on reflexes.
• 2 - 3 months: increased activity in cortex.
• 8 - 9 months: increased activity in frontal cortex.
Child brain development
• Synaptic Pruning: unused synapses are eliminated:
- Connections peak between 6-7 years.
• Neurogenesis: creation of new neurons.
- Humans produce new cells in olfactory bulb and primarily hippocampus.
- New cells migrate to other regions of the brain and form connections with existing cells.
- Associated with learning
Teen brain development (white and grey matter)
• White Matter:
- Myelinated neurons facilitate communication between regions.
- Growth increases between childhood and puberty, then slows:
• Grey Matter:
- Information processing.
- Second round of synaptic overproduction & pruning decreases volume.
Teen brain development (prefrontal cortex)
• Prefrontal cortex:
- Changes most pronounced and continue until mid-30s.
- High-level cognitive functioning (planning, organization).
- Strengthen connection to limbic system: Impulsive and subject to peer pressure.
Cognitive Development theorists and what they achieved
• Jean Piaget (1896 - 1980): Swiss developmental psychologist working with Theodore Simon.
- Interested in childhood thought processes leading to incorrect answers on IQ test.
- Four-stage model of cognitive development.
Assimilation and Accomodation
• Assimilation: interpreting new experiences in terms of existing mental structures. (A child who has a schema for “dog” (four legs, barks) might see a cat and, because it fits the existing “dog” schema, call it a “dog”)
• Accomodation: changing existing mental structures to explain new experiences. (The child who called the cat a “dog” will eventually need to accommodate this new information. They will either adjust the “dog” schema or create a new one for “cat” to account for the differences in sound and behavior.)
Sensorimotor Period
• Birth to age two; dominated by innate reflexes.
- Coordination between sensory input and motor actions.
- Symbolic thought begins to develop (e.g., mental image of favorite toy).
• Object permanence: recognition that objects continue to exist in the absence of sensory stimulation. (Play peekaboo with babies)
- Four months: no permanence.
- Four to 8 months: partial permanence.
- 18 months: permanence mastered.
Preoperational Period
Ages 2 to 7; development of symbolic thought continues.
Conservation: awareness that physical quantities remain constant in spite of changes in shape or appearance.
Characteristics of preoperational thought:
- Centration: focus on one feature of a problem.
- Irreversibility: inability to envision reversing an action.
- Egocentrism: inability to share another’s viewpoint.
- Animism: belief that all things are living.
Concrete Operational period
• Ages 7 to 11: operations performed on tangible objects.
- Reversability.
- Decentration.
- Decline in egocentrism.
• Conservation of liquid, mass, number, area, and length.
• Hierarchical classification: problems that require two levels of classification (e.g., 7 carnations, 3 daisies).
• Can’t think abstractly.
Formal operational period
Beginning at 11 years; applies operations to abstract concepts (justice, love, free-will).
Further development reflect changes in degree.
- More systematic in problem-solving, less trial & error.
Evaluating Piaget’s theory:
- Sequence of stages is constant, timetable variable.
- Doesn’t account for individual differences.
- Evidence of mixing elements of different stages.
Cognitive development
• Habituation dishabituation paradigm:
- Habituation: infant looses interest in stimulus presented repeatedly (heart-rate; respiration; looking time).
- Dishabituation: new stimulus elicits interest from infant.
- What type of events surprise infants?
• Four month olds understand:
- Add and subtract small numbers.
- Objects are distinct entities.
- Objects move in continuous paths.
- Solid objects cannot pass through each other.
- Objects cannot pass through openings smaller in size.
- Objects on slopes roll down.
Theory of mind
• The nature of “mind”.
- Ability to recognize other minds are distinct from own.
- Ability to know other minds have different content.
- Ability to anticipate the content of other minds.
- Ability to know that thoughts and desires motivate behaviour.
- Ability to recognize that not all thoughts reflect reality (False Belief).
• False Belief Task (thinks everyone know what they’re thinking):
- Theory of mind develops at about four years of age.
Moral reasoning
• Morality: ability to discern right from wrong and to behave accordingly.
• Moral Judgements: how good or bad is an action?
The 6 stages of morality
• Lawrence Kohlberg (1927 - 1987): American psychologist who worked with Piaget
- punishment orientation
- Naive reward orientation
- good boy/girl orientation
- authority orientation
- social contract orientation
- individual principles and conscience orientation
Motor development
Muscular coordination for physical activity.
Maturation: gradual unfolding of genetic blueprint:
Early development (e.g., grasping).
Requires environmental input (exploration).
Specialized skills develop later and require training (e.g., triple-axel).
Developmental benchmarks
Cephalocaudal Trend: progresses from head to foot.
Proximodistal Trend: progress from torso to limbs.
Great variation in development of benchmarks.
Identity status and who determined the 2 dimensions
James Marcia (SFU): identity status determined by 2 dimensions:
Presence/absence of a sense of commitment to life goals/values.
Sense of crisis (active questioning and exploration of identity).
Move between identity statuses.
Identity moratorium & achievement increase with age.
Identity changes across adulthood.
“Identity crisis” can occur in midlife.
The 4 identities
- Identity achievement (successful achievement of a sense of identity)
- Identity moratorium (active struggling for a sense of identity)
- Identity foreclosure (unquestioning adoption of parental or societal values)
- Identity diffusion (absence of struggle for identity, with no obvious concern about it)
Transitions during adulthood
Marriage.
- Median age increasing since 1970s.
- Median age decreased from 1920s to 1970s.
Parenthood.
- Rewarding experience.
- More stress!
Empty nest.
- Less stress!
- Marital & life satisfaction increase.
