Session 2: Prenatal development - Nature or Nurture

Nature vs. Nurture: What is innate? What is taught?

• John Locke (1632-1704)

  • Tabula rasa

  • Socio-political context of the time (Enlightenment)

• Physical or psychological tabula rasa? → how we are socialized into society

Nature vs. Nurture: What can be taught?

• John B. Watson (1878-1958)

  • Behaviourism: believes all our behaviors can be taught

  • 1913 - Behaviorist Manifesto

• Little Albert Experiment → association w/ sound; taught to be scared of animals, and experimenting based on Pavlov

Genetics

• Francis Galton (1822-1911)

  • Measuring human abilities, ranking

  • inspired by phrenology (pseudoscience)

  • normality, normal distribution

  • deficit, diversion

• Intelligence testing

  • Founder of eugenics

Eugenics

• Eu = goods

• genics = genes

  • Social Darwinism - “survival of the fittest”→ who survives, most adaptable

• Positive eugenics // negative eugenics = people who shouldn’t pass down genetics

Critical period

a specific time during development when a particular event has its greatest consequences and the presence of certain kinds environmental stimuli is necessary for development to proceed normally

Sensitive Period

a point in development when organisms are particularly susceptible to certain kinds of stimuli in their environments, but the absence of those stimuli does not always produce irreversible consequences

Critical & Sensitive Period Windows

Summary

• Human development reflects an interplay of genetic and environmental factors, not a simple either/or

• Historically, environmental influences were emphasized before genetic ones - understanding of genetic influence matured mainly in 20th century

• Twin studies gave psychology its clearest evidence for disentangling nature and nurture

• Eugenics (Galton) pushed the “nature” extreme, arguing skills and traits are shaped almost entirely through conditioning

• Research ethics matter on two levels: the ethics of individual studies (Little Albert, twin studies) and the ethics of the broader scientific enterprise (eugenics)

• Every theory we have covered was shaped by its socio-political and historical moment - a reminder to read psychological ideas in context