"When the Okies left Oklahoma and moved to California, they raised the average intelligence level in both states."
migrate
🔑 The Key Insight
The migrant is the lowest in Group A but higher than average in Group B.
Removing the lowest raises Group A's average. Adding someone above average raises Group B's average. Both go up!
The magic zone: Anyone with IQ between Oklahoma's lowest and California's average can raise both!
📜 Historical Context
The joke predates Will Rogers and has been told about various states and countries. Dr. Alvan Feinstein coined "Will Rogers Phenomenon" in 1985 while studying cancer staging, where improved diagnostics moved patients between stages—raising survival rates in ALL stages without improving any individual outcome!
Cancer Staging Example
Better imaging detects hidden metastases, "upgrading" patients from Stage I to Stage II. These patients were the worst in Stage I but are the best in Stage II—so both stages show improved survival!
⚠️ Both stages show "improvement" but NO individual patient got better!
Real-World Examples
- Lung cancer staging with CT scans (1985 study)
- Breast cancer with improved imaging
- Multiple sclerosis with MRI (McDonald criteria)
- Prostate cancer with PSA testing
- School "tracking" systems moving students between levels
Why This Matters
When comparing treatments across eras, "improved survival rates" might just be stage migration, not better treatment! Clinical trials must use historical controls carefully. A "breakthrough" could be an illusion created by reclassification.