The game where an all-knowing predictor already knows your move
Imagine a supercomputer that perfectly predicts human choices. It presents you with two boxes: Box A contains $1,000. Box B contains either $1 million or nothing. You can choose both boxes, or only Box B. The catch? The computer already predicted your choice. If it predicted you would take both, it left Box B empty. If it predicted you would take only B, it put the million inside. What do you do?
The Rules of the Game
Imagine an extraordinarily capable predictor—whether an advanced supercomputer, an alien intelligence, or a master neuroscientist—with a virtually flawless record of anticipating human behavior. This predictor invites you to play a game with two opaque boxes on a table, labeled Box A and Box B. Box A is known to contain $1,000. Box B contains either $1,000,000 or nothing at all.
You are offered a choice: you may take the contents of both boxes, or you may take only Box B. The catch lies in what happened before you sat down. Ahead of your arrival, the predictor evaluated your psychological profile and made a forecast of your decision. If it predicted you would choose only Box B, it deposited $1,000,000 inside Box B. If it predicted you would take both boxes, it left Box B completely empty. The predictor's choice has already been made, the boxes are sealed, and no changes will occur after you sit down. The question is straightforward: should you take both boxes or just Box B?
The Birth of Newcomb's Paradox
This thought experiment was devised by physicist William Newcomb of the Lawrence Livermore Laboratory in the 1960s. It might have remained an obscure puzzle among physicists if not for philosopher Robert Nozick, who introduced it to the wider academic community in a 1969 philosophical paper. Nozick realized that Newcomb's scenario was not merely a brainteaser, but a profound rupture in decision theory.
In his initial paper, Nozick famously observed that almost everyone finds the correct course of action immediately obvious, yet people divide into two sharply opposing camps. One group believes it is utterly self-evident that you should take only Box B, while the other believes it is equally obvious that you should take both boxes. Each group tends to view the other as completely irrational, exposing a fundamental disagreement in how humans understand rationality, causality, and choice.