Sapolsky Lecture 1 — Learning Log

Human Behavioral Biology · Stanford · Why zebras don’t get ulcers

Author

Laith Zumot

Published

March 7, 2026

Working notes. Source: Lecture 1 on YouTube

What he said

  • Behavior cannot be explained by any single cause.
  • Nature and nurture are not separate — they are one continuous process.
  • Every level (neural, hormonal, genetic, environmental) is just where you pause the tape.

What I think

  • The genome is a policy, not a law of physics.
  • Gene + environment + timing is the real unit of analysis.
  • Epigenetics is proof that nature and nurture interact.
  • There is no clean causation loop i can think of here without recursion.
  • There is an arrow from evolution back to behavior that I can’t explain yet ,but I know it’s there.

What I wonder

  • Why do we focus on individual behavior when no behavior is isolated from other people’s behavior?
  • Was the soldier’s stress response his nature, or was the war his environment? did he choose to go?
  • Where do other humans end and “environment” begin?
  • Is grandma’s lupus really in the baby’s epigenome?
  • Does methylation-as-damage and methylation-as-regulation eventually converge?