Human Development (How?)

→ broader than age (includes behavior, body, relationships, personality)

"What is the fundamental nature of the human being before it is shaped by society, and how do we become corrupt or fulfilled?"

  • augustine - original sin

    • humans are born selfish & stubborn, where caregivers promote moral development via discipline, restraint & correction.

  • locke - blank slate

    • humans are born as a blank slate, and their environment/childhood experience shapes them.

  • rousseau - innate goodness

    • humans are born good & naturally seek out experiences that support that growth, however with society, can be toxic/harmful.


→ observation replaced speculation (darwin with evolution, hall with scientific child study, gesell with milestone testing & piaget with cognitive development stage theory)

→ canada’s contributions:

  • william blatz (1920s) - founded a toronto school for child studies; security theory (trust your caregivers, be confident uncertainty = okay)

  • mary ainsworth - attachment research

  • wartime childcare (developmental knowledge applied to child-care problems with british children separated from caregivers)


→ lifespan perspective changes the initial idea of how humans develop

  • lifelong (meaningful gains/losses/stability/adaptation from conception to adulthood)

  • contextual (culture/historical period/relationships etc. shape life changes)

  • multidisciplinary (understanding development requires others like bio/psych etc.)

  • plastic (although limited later in life, humans have a capacity for change)


→ domains of development (which affects each other)

  1. physical

  2. cognitive

  3. social


→ developmental changes (human growth is both!)

  • continuous change (quantitative)

    • development = gradual, cumulative process (e.g. height increases)

    • different in amount

  • discontinuous change (quantitative)

    • development = abrupt, distinct stages (e.g. reproductive capacity)

    • different in kind (type)


→ sources of developmental change

  • universal - changes presumed to be common because everyone nearly experiences it

  • group specific - changes linked to culture/cohort/historical events

  • individual - changes shaped by unique/unshared experience/genotype


Nature & nurture work together

genetic info inherited at conception & the observable characteristics of those genetics in development interact with physical/social conditions, where genetic influences can shape responses to those conditions.


→ importance of timing of an experience

  • critical period - absolute, rigid, biological window (miss it → developmental deficit)

    • e.g. baby ducks imprinting on the first moving object they see

  • sensitive period - flexible, optimal window as it’s when an individual is most responsive to an experience (though possible for development to occur later)

    • language learning as a child (easier) vs as an adult (harder, not impossible)