Abstract
Turkheimer states three laws of behaviour genetics — everything is heritable, nothing is 100% heritable, heritability is context-dependent — cooling overheated nature–nurture wars.
Turkheimer, E. (2000). Current Directions in Psychological Science, 9(5), 160–164. DOI
Key findings
- First law — Everything is heritable — some genetic influence on virtually every trait studied.
- Second law — Nothing is 100% heritable — environment always shares variance.
- Third law — Heritability changes by context — same genotype, different expression.
- Debate cooler — Laws reframe political fights as empirical, not moral-only.
Limits
Commentary — laws are statistical summaries, not individual fate.
Application
When someone says it’s all genes or all choice — heritability is real and partial, and context shifts the split. See Hardwired biological constraints.