Galton, Woodworth, and Watson

 The ongoing shift from biological determinism (Galton) and radical behaviourism (Watson) to interactionist models (Woodworth) directly reflects how we understand human development, personality, and mental health today.

 Understanding Nature vs Nurture: Aspect: Nature (Genetics & Biology) Nurture (Environment & Experience) Core Idea: Inborn physical, psychological, and neurological traits governed by DNA.

 External influences, relationships, learning, and cultural environment.

 Key Factors•

 Inherited genetic codes•

 Brain structure and neurochemistry•

 Innate reflexes and physiological predispositions• Early childhood caregiving and attachment style• Social relationships and community support• Life stress, trauma, exposure, and culture Role in Mental Health Genetic vulnerabilities (e.g., family history of mood disorders) and neurotransmitter imbalances.

Traumatic events, chronic environmental stress, isolation, and coping mechanisms learned over time.

 The Modern Synthesis: Gene-Environment Interaction Rather than asking whether a trait is caused by nature or nurture, contemporary science views human development as a dynamic, ongoing conversation between both:    ┌──────────────────────┐

    │ Genetics (Nature)    │ ───► Inborn potential & biological vulnerabilities

    └──────────┬───────────┘

               │

               ▼  (Interacts constantly via Epigenetics & Environment)

    ┌──────────────────────┐

    │ Environment (Nurture)│ ───► Expression of genes & shaped behavior

    └──────────┬───────────┘

               │

               ▼

   [ Final Human Behavior & Health Outcome ]

Epigenetics: Environmental conditions (such as severe stress, nutrition, or supportive relationships) can physically alter gene expression—turning specific genetic markers on or off without altering the underlying DNA sequence.

Mental Health Outcomes: A person may inherit a biological predisposition toward anxiety or depression (Nature), but whether that condition manifests often depends on environmental stressors, support systems, and life experiences.

 (Nurture).

Capacity vs. Expression: Biology establishes the underlying capacity and biological baseline, while environmental experiences shape how that potential is structured, expressed, and utilized throughout a person's life.