The Bayesian Trap

Bayes' theorem explained with examples and implications for life.

I didn't say it explicitly in the video, but in my view the Bayesian trap is interpreting events that happen repeatedly as events that happen inevitably. They may be inevitable OR they may simply be the outcome of a series of steps, which likely depend on our behaviour. Yet our expectation of a certain outcome often leads us to behave just as we always have which only ensures that outcome. To escape the Bayesian trap, we must be willing to experiment.

Special thanks to Patreon supporters:
Tony Fadell, Jeff Straathof, Donal Botkin, Zach Mueller, Ron Neal, Nathan Hansen, Saeed Alghamdi

Useful references:
The Signal and the Noise, Nate Silver
The Theory That Would Not Die: How Bayes’ Rule Cracked the Enigma Code, Hunted Down Russian Submarines, and Emerged Triumphant from Two Centuries of Controversy, by Sharon Bertsch McGrayne

Bayes' theorem or rule (there are many different versions of the same concept) has fascinated me for a long time due to its uses both in mathematics and statistics, and to solve real world problems. Bayesian inference has been used to crack the Enigma Code and to filter spam email. Bayes has also been used to locate the wreckage from plane crashes deep beneath the sea.

[eiccio]

the guy that found the formula in Bayes’s papers after death and still gave credit to Bayes without trying yo appropriate it for himself is truly a man of science

[pamphlet]

"So what do you do for a living?"
"Oh the usual, drive to an open field, walk a mile, and talk to myself for a bit."

[mobius]

came for the mathematical insight, stayed for the existential crisis

[BC-yvew]

One of the best pieces of advice I’ve gotten is to always leave yourself room to be wrong. It infuses a certain amount of humility into things. Feels like this is the mathematical proof that advice.

[caio.tavares]

This 10 minute video was better at teaching Bayes Theorem than my whole Stochastic Processes class in the university.

[indylockheart]

"Well this can't be good." The first caveman to witness a sunset probably

[declination]

“Keep the company of those who seek the truth- run from those who have found it.” ― Vaclav Havel

[irfankarim]

I watched this video again after 6 years. A lot of things have changed for me, you made science interesting and then there was no looking back for me. I love you, Dr. Derek Muller. Cheers to the day you decided to leave your full-time job as a professor and started to make these videos that can reach so many more people.

[RichardBuckerCodes]

I really like the bit about 0% or 100% certainty.... it explains a lot of things.

[chloemccarthy]

I needed this video. I needed to know that a famous mathematician had doubts their research was worth publishing.

[shawnnoyes]

Yes, this video inspired me to go back to school, and finish my degree. Class started today.
Thanks!
-Shawn

[anandanarayanan_n_]

This is the kinda content I want, I don't want a long commentary on advancing tech or difficult problems, i want simple explanation of fundamental and simple principles and their meaning in our everyday lives
Great work veritasium

[jonwatte]

The 91% is only true if the second test is statistically independent.
In practice, causes for false positives may be correlated, eg genetics or other factors triggering the indicator in the test, being tied to the person.

[ffttossenz]

Normal probability YouTube tutorial: some dude in front of a white board
Veritasium: walking in nature talking about men in caves

[pcsecuritychannel]

Great video. This is the kind of content I love to see. I don't care about the editing or production quality, as about the depth of content, the concept, and how well it is explained. Keep it up, Derek.

[lakshannavarathna]

I absolutely love this video. The first time I learnt Bayers theorem, like you said it really felt counter intuitive. But the you see the Bayesian nature of real life decisions. You can never make a calculated guess about the final outcome without the knowledge of its prior. The only case that you’d know for certain is when your prior is either 0 or 1. It’s an amazing piece of mathematics.

[mediawolf]

I'm enjoying successively updating my understanding of Bayes' theorem by watching different people's takes on it. I also like that the moon is in this video.

[sjoerdstougie]

came for a mathematical fun fact, stayed for a life lesson :)

[LuciaFiero]

While I was recovering from cancer treatment my best friend died of cancer, while I was recovering from losing her, my mother died suddenly of cancer. Since my girlfriend's cancer came back 3 times before it killed her, I am haunted by the fear of recurrence, which has me stuck in a rut. My continuing weakness after treatment isn't helping.

When I started watching you this month, your enthusiasm penetrated my gloom, but just barely. The more videos I watched the more of your "expect the best" pep talks I've found, this being the latest.

I've made some plans this week for this coming winter and am resisting the thought that things will continue to go badly for me. I found myself Friday looking forward to something for the first time in a very long time. Today I invited friends to join me in my plans and they agreed. The nagging voice saying "it will all go wrong, " is still there, but I've decided to just be happy that I felt a modicum of enthusiasm for the future for the first time in a very long time. I will keep you posted if you are interested in my anecdotal evidence.

[TorQueMoD]

I heard the phrase years ago "If you do what you've always done, you'll get what you've always got". It's interesting to see the etymology of that concept. Thanks for sharing!