Gene-Environment Interaction Lecture Notes

Introduction

• Past videos discussed genes and environment related to behavior.
• Importance of both genes and environment.
• Interaction between genes and environment is crucial.

Key Concepts

• Interaction: The effect of genes and environment on behavior is interdependent.
• Example: Tea in hot water analogy to illustrate interaction.

Case Study: Babies in a Nursery

• Two babies, one more attractive than the other.
• Attractive baby vs less attractive baby:
  • Attractive baby receives more affection, becomes sociable and well-adjusted.
  • Both babies predisposed to depression.
  • Environment activates depression genes:
    • Attractive baby has supportive environment, less stress, reduced gene activation.
    • Less attractive baby faces stress, activates depression-related genes.
• Conclusion: Genes and environment both shape behavior.

Phenylketonuria (PKU) Example

• PKU: Genetic condition caused by mutations in the gene coding for liver enzyme phenylalanine hydroxylase (PAH).
  • Leads to build-up of phenylalanine, affecting brain development.
• Incidence: Affects 1 in 15,000 babies in the US.
• Management:
  • Identified through infant screening.
  • Managed with a phenylalanine-free diet, preventing build-up.
• Conclusion: Interaction of genes and environment influences body responses and behavior.

Gene/Environment Interaction

• Environment is dependent on genetic predisposition.
• Gene expression is also affected by the environment.
• Shift from "nature vs nurture" to "nature through nurture."