Nature vs. Nurture and Epigenetics

Jun 22, 2024

Nature vs. Nurture and Epigenetics

Introducing Lucky Lyle and Trouble Tim

  • Identical twins raised in different environments:
    • Lucky Lyle: Model citizen, works, pays taxes, educated
    • Trouble Tim: Criminal, robs banks, doesn't pay taxes, imprisoned

The Big Question: What Makes Us Us?

  • Early explanations: Supernatural
  • Emergence of science led to two main theories:
    • Nurture: Environment shapes us (social sciences)
    • Nature: Genes as unchangeable blueprints (biological sciences)

Introduction to Epigenetics

  • Epigenetics: Interaction between genes and environment
  • Key question by researcher Michael Meany: What makes a good rat mama?

The Rat Mama Study

  • Licking as a sign of motherly care:
    • High-licking mothers = loving and caring
    • Low-licking mothers = less nurturing
  • Findings: Babies of high-licking mothers grow up to be high-lickers regardless of genetics

Cross-Fostering Experiment

  • Method: Swapping babies between high-licking and low-licking mothers
  • Result: Mother’s behavior influences baby’s behavior, not genetics
  • Scientific Dive: Brain examination showed differences in genes related to motherly care

Methyl Groups and Genetic Expression

  • Newborn rats: Methyl groups attached to genes, silencing them
  • High-licking mothers: Methyl groups disappear, genes get expressed

Implications for Humans

  • Similar effects in humans:
    • Environmental influences (e.g., nutrition, exercise, smoking, stress, love) affect biology
    • Changes observable at the DNA level
  • Epigenetic changes: Continuous throughout life, lifestyle choices can influence development

Conclusion

  • Nature vs. Nurture: Both factors contribute but interact through epigenetics
  • Empowering message: Our choices and environment significantly influence our genetic expression and development.