This Paradox Splits Smart People 50/50

Veritasium25m 40s

The video explores Newcomb's paradox, a thought experiment involving a supercomputer that predicts whether you'll take one or both boxes, with the prediction determining if $1 million is placed in the mystery box. The paradox splits people roughly 50/50 between 'one-boxers' and 'two-boxers', revealing fundamental differences in decision-making approaches.

Summary

Derek presents Newcomb's paradox, where participants face a choice between taking just a mystery box or taking both a mystery box and a visible box containing $1,000. A highly accurate supercomputer has already predicted their choice and placed either $1 million (if predicting one-box choice) or nothing (if predicting two-box choice) in the mystery box before they arrive. The video demonstrates how this seemingly simple problem divides intelligent people into two camps. One-boxers use evidential decision theory, arguing that since the supercomputer has been accurate with thousands of previous participants, choosing one box correlates strongly with receiving $1 million. Two-boxers use causal decision theory, arguing that since the prediction is already made, they should always take both boxes to maximize their outcome regardless. The discussion extends beyond the paradox to explore deeper philosophical questions about free will, rationality, and optimal decision-making strategies. The video draws parallels to nuclear deterrence strategy during the Cold War and the prisoner's dilemma, showing how pre-commitment to seemingly suboptimal choices can lead to better outcomes. The speakers explore whether rationality means making the best choice in the moment or committing to rules that produce the best long-term results across multiple scenarios.

About this episode

Two boxes, one choice, and $1,000,000. Sponsored by Brilliant - To learn for free on Brilliant for a full 30 days, go to https://brilliant.org/veritasium. Our viewers also get 20% off an annual Premium subscription, which gives you unlimited daily access to everything on Brilliant. If you’re looking for a molecular modelling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV Sign up for the Veritasium newsletter for weekly science updates - https://ve42.co/Newsletter ▀▀▀ A huge thank you to Dr. Arif Ahmed, Dr. Adam Elga, Dr. Kenny Easwaran, Dr. Peter Slezak, Dr. David Wolpert, Dr. Scott Aaronson & Dr. Michael Huemer for their invaluable expertise and contributions to this video on Newcomb’s Paradox. The causal expected utility calculation was based on a post by Professor Huemer here - https://ve42.co/Huemer ▀▀▀ 0:00 What is Newcomb’s Paradox? 3:24 Pick 1 Box! 5:24 Pick Both! 6:38 What is decision theory? 11:27 What does Newcomb’s Paradox say about free will? 13:25 What does it mean to be rational? 16:49 Mutually Assured Destruction 20:02 Precommitment Is The Ultimate Strategy ▀▀▀ References can be found here - https://ve42.co/NewcombRefs ▀▀▀ Special thanks to our Patreon supporters: Albert Wenger, Sam Lutfi, Michael Krugman, Sinan Taifour, Marinus Kuivenhoven, Lee Redden, Richard Sundvall, Ubiquity Ventures, David Johnston, Juan Benet, Paul Peijzel, Meekay, Evgeny Skvortsov, Blake Byers, Dave Kircher, Gnare, Anton Ragin, KeyWestr, meg noah, Tj Steyn, Orlando Bassotto, Adam Foreman, Balkrishna Heroor, Jesse Brandsoy, Garrett Mueller, Kyi, Ibby Hadeed, Bertrand Serlet, wolfee, David Tseng, Bruce, Alexander Tamas, Alex Porter, Jon Jamison, Charles Ian Norman Venn, armedtoe, Jeromy Johnson, Hayden Christensen, Robson, EJ Alexandra, Daniel Martins, Shalva Bukia, Moebiusol - Cristian, Martin Paull, Data Don, Vahe Andonians, Mark Heising, Hong Thai Le, Parsee Health, Kelcey Steele ▀▀▀ Writers: Sulli Yost & Casper Mebius Producer & Director: Sulli Yost Editor: Jack Saxon Additional Editing: Peter Nelson Camera Operators: Lukas Guderjahn, Danijela Čavlović, Casper Mebius, Gregor Čavlović & Derek Muller Presenters: Casper Mebius, Gregor Čavlović, Henry van Dyck & Derek Muller Animators: Emma Wright, Andrew Neet, Alex Drakoulis, Domonkos Józsa & Fabio Albertelli Assistant Editor: James Stuart Researcher: Darius Garewal & Gabe Strong Thumbnail Designers: Abdallah Rabah, Ren Hurley & Ben Powell Production Team: Jess Bishop-Laggett, Matthew Cavanagh, Anna Milkovich & Josh Pitt Executive Producers: Casper Mebius & Derek Muller Additional video/photos supplied by Getty Images & Storyblocks Music from Epidemic Sound

Key Insights

  • Robert Nozick observed that people divide almost evenly on Newcomb's paradox, with each side thinking the opposite half is being silly, despite both having seemingly obvious reasoning
  • One-boxers use evidential decision theory based on the supercomputer's track record, calculating that if the computer is better than 50.05% accurate, one-boxing has higher expected utility
  • Two-boxers employ strategic dominance reasoning, arguing that regardless of what's in the mystery box, taking both boxes always yields $1,000 more than taking just one
  • Philosophers Gibbard and Harper argued in 1978 that rational choice is to pick both boxes, even though they admit two-boxers will fare worse, calling the game rigged to reward predicted irrationality
  • The paradox reveals that sometimes to be a rational person, you must act irrationally, and that rational societies might be full of people who don't always make individually rational acts

Topics

Newcomb's paradoxdecision theoryevidential vs causal reasoningfree will and determinismgame theory and pre-commitmentnuclear deterrence strategyrationality and optimal decision-making

Transcript

[0:00] - There is a problem that I can't bring up without starting a fight. - No, what? - It just seems so obvious to me. - Now I'm all screwed up, man. (Casper laughs) - It has infiltrated every single Veritasium meeting in the last two months. - It's trivial. (laughs) - I didn't think you would fall for this side. - Just makes sense. - Let's go! - That's crazy! - And I even argued with Derek about it. - There's no way you're trying to convince me. I don't care. - So, here's the setup. You walk into a room, and there's a supercomputer and two boxes on the table. [0:31] One box is open, and it's…

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