CHYS 1F90 Developmental Science Key Concepts Summary

Posted on Feb 27, 2026 in Early Childhood Education Teacher (Teaching Degree)

CHYS 1F90 – Comprehensive Exam Summary

Part 1: Foundations of Development

A. Genetics & Prenatal Development

  • Conception: 46 chromosomes (23 from each parent).
  • Gene Expression: Dominant vs. recessive genes, polygenic inheritance.
  • Chromosomal Abnormalities:
    • Down Syndrome (Trisomy 21).
    • Turner Syndrome (X–), Klinefelter (XXY).
    • Caused by inherited or *de novo* mutations.
  • Prenatal Stages:
    • Zygote: Conception to implantation.
    • Embryo: Weeks 3–8 (organ development).
    • Fetus: Weeks 9–birth (maturation).
  • Teratogens: Viruses, drugs, chemicals, radiation (FASD, rubella, toxoplasmosis).
  • Maternal Stress: Cortisol affects fetal development.

B. Neurological Development

  • Neurons: Specialized cells for information processing.
  • Synaptogenesis: Experience strengthens synapses.
  • Neural Pruning: “Use it or lose it”—41% fewer neurons in adults vs. newborns.
  • Critical Periods: Windows for optimal development (e.g., language).
  • Neural Sculpting: Environment shapes brain pathways.
  • Key Studies: Genie (language), Rhesus monkeys (stress buffering).

C. Developmental Theories

  1. Freud: Psychosexual stages (oral, anal, phallic, latency, genital).
  2. Watson/Skinner: Behaviorism—environment shapes behavior.
  3. Piaget: Cognitive development, schemes, equilibrium.
  4. Bronfenbrenner: Ecological systems (micro, meso, exo, macro).
  5. Bach: 6-stage theory of self-development.

D. Risk & Protective Factors

  • Risk Factors: Increase poor outcomes (poverty, family violence, temperament).
  • Protective Factors: Increase good outcomes (supportive parents, good health).
  • Cumulative Effects: Multiple factors combine.
  • Nature Through Nurture: Genes and environment interact.

Part 2: Adolescence

A. Neurological Basis

  • Frontal Lobe: Not fully developed until early 20s.
    • Executive functions: planning, decision-making, self-regulation.
  • Amygdala Dominance: Teens use the emotional brain for decisions.
  • Neurochemicals:
    • Serotonin (calming) fluctuates.
    • Dopamine (reward) peaks.
  • Myelination: Not complete until early adulthood.

B. Adolescent Behavior

  • Statistics: High risk-taking (alcohol, drugs, unprotected sex, reckless driving).
  • Reasons: Short-term focus, emotional reactivity.
  • Positive Risk-Taking: Calculated risks lead to well-being, confidence, and resiliency.
  • Sleep: Melatonin released 2 hours later; need 9 hours (usually get 6).
  • School Policies: Later start times are supported by research.

C. Cultural & Social Aspects

  • Social Construct: Adolescence varies across cultures.
  • Dutch vs. American: Different parenting approaches to teen independence.
  • Fostering Independence: Allow decision-making, responsibility, and mistakes.
  • Case Study: Omar Khadr—developmental immaturity defense.

Part 3: Social Neuroscience & Stress

A. Loneliness & Social Connection

  • Loneliness Epidemic: Especially 14–25 age group, worsened by COVID.
  • Health Risks: Equivalent to smoking 15 cigarettes/day.
    • Links to heart disease, stroke, dementia.
  • Physiological Effects:
    • Increased inflammation.
    • Body interprets loneliness as stress or pain.
  • Evolutionary Perspective: Social pain uses the same neural pathways as physical pain (biological piggybacking).

B. Stress Physiology

  • Cortisol Effects:
    • Suppresses the immune system.
    • Impairs cognitive functioning.
    • Links to cancer and inflammation.
  • Cellular Stress Memory: Prolonged stress causes lasting cellular changes.
  • Mitochondrial Damage: Compromises cell energy production.
  • Sudden Adult Death: Can be triggered by emotional stress.

C. HPA Axis & Inflammation

  • Social disconnection $\rightarrow$ increased inflammatory activity.
  • Inflammation = immune response to perceived threat.
  • Chronic stress $\rightarrow$ compromised immune function.

Part 4: Mental Health Disorders

A. Depression

  • Characteristics: Poor performance, withdrawal, sadness, anger, sleep/eating changes.
  • Prevalence: 1% preschoolers, 2–3% elementary, 6–20% adolescents.
  • Causes: Neurotransmitter imbalance (serotonin, dopamine), genetics (40–50%), environment.
  • Treatment: SSRIs (Prozac, Zoloft), social support.
  • Outcome: 80–90% respond well to treatment.

B. Anxiety Disorders

  • Continuum: Related to stress; problematic when it interferes with functioning.
  • Types: GAD, phobias, social anxiety, PTSD, OCD, panic.
  • Cortisol: Suppresses immune and cognitive functioning.
  • Treatment: CBT, medication (SSRIs, SNRIs).

C. Bipolar Disorder

  • Characteristics: Extreme mood swings (mania & depression).
  • Types: Bipolar 1 (severe mania), Bipolar 2 (severe depression), Cyclothymic.
  • Causes: Strong genetic link (70% heritability).
  • Treatment: Mood stabilizers (Lithium), psychotherapy.
  • Lithium Effect: Stabilizes cortisol cycling.

D. Schizophrenia

  • Characteristics: Confusion between real/unreal (not split personality).
  • Onset: Adolescence (men: 18, women: 25).
  • Symptoms: Positive (hallucinations, delusions), Negative (low energy).
  • Causes: Excessive dopamine, genetic vulnerability, viral infections (Toxoplasma).
  • Treatment: Antipsychotics (block dopamine), behavioral therapy.
  • Alternatives: Hearing Voices Network (not a disease).

E. ADHD

  • Characteristics: Behavioral disability, often comorbid with LD.
  • Causes: Lower brain activity in attention areas, chemical imbalance, highly heritable.
  • Treatment: Stimulants (Ritalin), behavior modification.
  • Statistics: 2.5 million children medicated; 80% respond positively.

F. Autism Spectrum Disorder

  • Characteristics: Social communication deficits, repetitive behaviors, sensory sensitivities.
  • Causes: Genetic + environmental factors.
  • Treatment: Behavioral interventions (ABA); no pharmaceuticals.
  • Mirror Neuron Dysfunction: Possible basis for ASD.

G. Learning Disabilities

  • Statistics: 80% are reading disabilities.
  • Neurological Basis: Dysfunction in temporal/parietal lobes.
  • Genetics: DCDC2 gene mutation associated with RD.
  • Interventions: Orton-Gillingham, Lindamood Bell.

Part 5: Population & Developmental Health

A. Key Concepts

  • Population Health: Improve health of the entire population.
  • Developmental Health: Physical, mental, social, cognitive, and educational development.
  • Social Determinants: SES, education, relationships, government, policies.
  • SES Gradient: Strong association between socioeconomic status and health.

B. Policy & Interventions

  1. Ready! For Kindergarten: 90% reading goal, 80% fewer in special ed.
  2. High/Scope Perry Preschool: Long-term benefits for at-risk children.
  3. Kangaroo Care: Effective for premature babies.
  4. Cuba’s Polyclinics: Community-based, preventive, no-cost care.
  5. Caregiver Leave: Supports early language development.

C. Social Determinants

  • SES Measures: Education, income, occupation.
  • Disparities: Income inequality linked to health outcomes.
  • Mothers’ Speech: Amount of talking correlates with infant vocabulary.
  • Policy Focus: Support lower SES, reduce income disparity.

Part 6: Well-Being & Empathy

A. Self-Confidence & Resilience

  • Components: High self-esteem, sense of control, social health, independence.
  • Development: Gradual, through self-understanding and social awareness.
  • Reframing: Separate self from emotions (“This is anger” not “I am angry”).

B. Mindfulness

  • Effects: Reduces amygdala response, lowers cortisol, improves academics.
  • Strategies: Meditation, Spidey-Sense, Nose Knows.
  • Polyvagal Theory: Green/yellow/red states of the nervous system.

C. Empathy

  • Definition: Understanding others’ perspective.
  • Neural Basis: Mirror neurons.
  • Deficit Causes: Cultural focus on self, lack of practice.
  • Teaching Strategies: Expand circle of care, modeling, mindfulness.
  • Programs: Roots of Empathy, Ashoka Changemaker Schools.

D. Future Skills

  • Unknown Future: 60% will work in jobs that do not yet exist.
  • Key Skills: Well-being, confidence, problem-solving, resiliency, critical thinking.

Part 7: Exam Strategies & Key Concepts

A. Cross-Cutting Themes

  1. Neural Plasticity: Brain changes with experience (Macaques study).
  2. Nature & Nurture: Interaction throughout development.
  3. Critical Periods: Windows for optimal development.
  4. Concordance Rates: Genetic vs. environmental influences.
  5. Research $\rightarrow$ Policy: Applying developmental science.
  6. Psychological Toolkit: Individual differences in coping.

B. Exam Writing Tips

  • Format: Full sentences, no bullet points.
  • Flow: Logical connections between ideas.
  • References: “In lecture we discussed…” without formal citations.
  • Length: Do not exceed page limits if specified.
  • Focus: Answer the question directly.

C. Important Statistics to Remember

  • Loneliness = 15 cigarettes/day risk.
  • Depression: 80–90% treatment responsive.
  • ADHD: 80% respond to medication.
  • LD: 80% are reading disabilities.
  • Schizophrenia: 1 in 100; 10% risk with an affected parent.
  • Adolescence: 70% of deaths from accidents/violence.

Memory Joggers:

Cortisol = Bad News:

  • Suppresses immune system.
  • Impairs thinking.
  • Links to disease.

Adolescent Brain = Under Construction:

  • Frontal lobe not done.
  • Amygdala in charge.
  • Sleep schedule different.

Social Pain = Real Pain:

  • Same brain pathways.
  • Evolutionary adaptation.
  • Health consequences.

Early Experiences Matter:

  • Neural sculpting.
  • Critical periods.
  • Lasting effects.

Genes + Environment = Outcomes:

  • Not either/or.
  • Interaction is key.
  • Can modify expression.