What Psychohistory Promises

Psychohistory, in Asimov's Foundation, is the mathematics of crowds: individual people are unpredictable, but populations — in their trillions — follow statistical laws.

The two assumptions

1. The population must be large enough for statistics to apply.
2. The population must remain unaware of the predictions, or it will change its behavior and invalidate them.

Why it resonates

Real fields echo the idea: epidemiology, macroeconomics, statistical mechanics. None achieve Seldon's precision — and the second assumption is the reason forecasting your own society is so hard.

Key takeaways

• Psychohistory predicts crowds, never individuals.
• Its power collapses if the predicted are told the prediction.
• Real-world analogues exist, but with far wider error bars.