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Believing is Seeing - How Bayesian Priors Trick Your Senses - Future IQ

5,920 views Wait, is this logic right? • Apr 18, 2025
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Slog Reference: Believing is Seeing: Understanding Bayesian Priors

Description

Do your beliefs shape what you see, hear, and think? Discover how your brain edits reality using Bayesian priors, the placebo effect, and weird brain tricks like the McGurk effect. This isn't just about illusions — it's about how your entire experience of the world is filtered through what you already believe.

In this episode of Future IQ, we explore how your mind doesn't passively receive information — it actively predicts it. What you see, what you hear, even what you taste can all be shaped by your past experiences, expectations, and unconscious biases. From System 1 and System 2 thinking, to real-life studies on motivated reasoning, political beliefs, and placebo responses, we show how your brain decides what’s “true” before you even realize it.

You’ll learn why two people can see the exact same thing but believe completely different stories, and how something as simple as a McDonald’s logo can actually change the way food tastes. We’ll explore why some beliefs become so strong they get “stuck,” refusing to change even when new evidence appears. You’ll also see how politicians use subtle signals — known as dogwhistles — to activate people’s beliefs without ever saying things outright. And most importantly, we’ll uncover why facts alone often don’t change minds but feelings do.

More Videos:
From Instinct to Insight - How Do We Really Decide?: https://youtu.be/9_Ffrs0YyX0
Rohit Sharma Lost 12 tosses in a row - Fixed or Coincidence?: https://youtu.be/EY4WCmIJLcY
Are You Not Good Enough? Imposter Syndrome: https://youtu.be/-gKO6EmQ3YM
Mastering Both Your Brains - System 1 and System 2: https://youtu.be/DIVTMooO7o4

SOURCES
Top-down processing in our brain and why it results in “believing is seeing”: https://slatestarcodex.com/2016/09/12/its-bayes-all-the-way-up/
McGurk effect: https://www.youtube.com/watch?v=2k8fHR9jKVM

Hope you enjoyed FutureIQ by Navin Kabra and Shrikant Joshi. Do hit us up on Twitter:
@ngkabra http://twitter.com/ngkabra
@shrikant https://twitter.com/shrikant

Listen it on the podcast provider of your choice: https://tapthe.link/FutureIQRSS

00:00 Believing is Seeing?
02:03 Even Your Ears Are Lying to You?
02:40 You’re Experiencing Placebo Effect
04:06 Priors Make you Stuck?
07:33 Major Example of Priors
09:19 Why Does Our Brain Work Like That?
10:56 Trapped Priors in Politics
12:44 Feelings Don’t Care About Facts
13:27 Can you Never Escape a Trapped Prior?

#futureiq #bayesianbelief

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Believing is Seeing: Understanding Bayesian Priors

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Transcript

Seeing is believing. Lots of people like to say, but in reality, the reverse is often true. Believing is seeing. What do you mean believing is seeing? Let me give an example. Look at this thing on screen. Uh, what are these dots? What is this black splotch? You have no idea what's going on, right? Zero. Okay, now look. Wait, is that a Dalmatian? It is, isn't it? Now look at the original image again without the red outline. I see the dalmission. There is no red outline. I I how do I still see the dalmation? Right?
So the point here what is happening is that you didn't see the dalmation when you didn't know what to look for. But once you know that there's a dalmatation there, now you can't unsee it. It is like right there. Right. Yeah. Yeah. I actually can't go back to the previous image where I didn't see the dalmation. This is what this episode is about. Okay. We think that what we believe is based on what we see, what we hear and other evidence we have gathered. Yeah. But in reality, what we see and what we hear depends on what we already believe.
Okay. Yeah. What's happening is our brain tells us what to look for and then we see it. Okay. So another example similar to what we saw earlier is this thing. See if you can see something in that. Right? And do comment and let us know what you see in this image that Naven has just shown. I think I see something but I'm not sure. So I want to sort of corroborate it with you. But let me take other examples. Okay. Okay. Look at this. What does it say? The cat. Look at the H in the and the A in cat. Yeah, they're same. They're exactly the same thing. But you had absolutely no problem seeing an H here and an A here. Right.
Yeah. That's because your brain was already telling your eyes what to see. It was Why? Why did it do that? Yeah. So, I have to now be careful of believing what I see. Not just what you see, what you hear. Also, check out this clip. Then van then then when then. So not just my eyes, my ears also. Well, it is much more than that, right? Even your tongue. Okay. What you taste also depends on what you believe. We will cover that in a separate episode. Okay. So I have to be careful of believing all my senses.
Well, not just your senses. It is beyond that much more. Okay. So for example, okay. Have you heard of the placebo effect? Yes, we have spoken about the placebo effect so many times. Yeah. 30 to 60% of patients experience the placebo effect which means that if they believe they're being treated for a medical condition, then they get better even if they're not being treated for that medical condition. So your body getting better is believing. Not just seeing is believing. Right. So um entire cancers have disappeared. Okay. Yeah.
Through the placebo effect. I've heard of several of those cases. Yeah. Lots of other little things also. Okay. Like children find fries tastier when served in a McDonald's bag. Okay. I'm sure adults also find them tastier if served in. But here's what I'm getting from all of this. This is reminding me of the episode that we did uh just previous to this one which is about Beijian prior. Yes, exactly. This is Beijian prior and in that episode we talked about how our priors what we believe already changes how we interpret evidence.
Right. Correct. This isn't happening just in our brains and our thoughts. Right. At the most basic level of our senses, the beliefs in our brain are telling us how to understand things in the world, what to sense. Yeah. But uh I remember we talked about it in the other episode also that if we keep updating our priors on the basis of evidence, then eventually we are going to reach some kind of a right conclusion. Right. Yeah. Well, no. That is the problem that you know you if you have a prior which is so strong that it is forcing you to misinterpret all the incoming evidence right then you are stuck. Okay, let's take an example. You have a phobia of a
dog, right? There are lots of people who have dog phobia. Why? Because once in their childhood, uh, you know, a dog bit them or something and it was like a very scary, nasty, very traumatic event. Yeah. Okay. Now, let us say that you want this person to be cured of the dog phobia, right? What do you do? You tell them see there is this really nice dog and you know you're going to sit next to that dog and it'll be fine right so what we are trying to do is give negative evidence to the Beijian prior so that the prior gets updated okay but the problem is that your brain which has a prior saying dogs are scary is telling
you dogs are scary so as soon as they bring a nice fluffy dog in here you get scared the fluffy ones are the scariest man right you get scared your heart starts beating faster. You produce adrenaline and all kinds of things are happening in your body covered in a different episode by the way. But the point is that this was a scary experience for you. Yes. Right. So you had a prior that if a dog comes it'll be a scary experience. Then you had a scary experience. So all that this thing achieved was reinfor Yeah. Yeah, I mean u and it happens in more normal situations also, right? Dog phobia is just a few person. But let's
say that you are a person who has low self-esteem and you want to go on a date with a hot person, right? You probably have a prior that you know that person anyway doesn't like you and it's going to be very awkward and like a really bad date. M and then as a result of that you are nervous and you are awkward and it turns out to be a bad date. Naven giving dating advice on future IQ. I never even thought of this situation as a possibility and it has happened. Yeah.
But another example. Okay. Uh this is a famous thing called [ __ ] eating crackers. What the point is that if there is a person that you really really hate, right? Then anything that that person do is like hateful, right? She just sits there eating biscuits and you're like [ __ ] eating crackers, right? I remember how that happens. Yeah, this was a viral meme from a while ago. It it sounded really weird coming from Naven, but now that he explains it in the context of prior and you know uh evidence and Beijian updating it, it starts to make a lot more sense. I want you to think about situations in your life where you
notice, oh man, that's a trap prior. That's why it never worked. You will come up with many. Yeah. Please let us know about those situations in the comments. And while you're typing also subscribe, follow etc etc. Give us a like, share the video. More people will watch it. More people will understand about their trapped prior. So you're saying when a prior is strong enough, it will color all future evidence and it itself, the prior itself will not change. Absolutely. And let me give you a more serious example of this. Okay.
Okay. There is one study in which people were given papers to read and they were asked whether the methodology of the paper was correct. Whether the way in which they did research was okay or was the paper itself flawed and the conclusion cannot be trusted because the methods were wrong. What was the research about? The research was about capital punishment, right? Death penalty. Okay. Death penalty. Are you pro or against? Okay. They intentionally chose papers which had good methodology. Mhm. Right. And half of them were pro death penalty. The other half were anti-death penalty. Okay. Okay. Now what happened was that people looked at the conclusion and if the conclusion was pro death penalty and the person was anti
the person said the methodology was flawed. Oh. And if the conclusion agreed with the person's belief then the person said the methodology was correct. Yeah. Okay. Oh. But just to especially prove this thing what they did was they gave the same papers flipped the conclusion. Oh okay. And now so now when the conclusion was flipped the paper now became made up. It's not the original conclusion of the original paper. Yes. Right. Okay. But now suddenly again the methodologies which were flawed earlier have become good methodologies and the methodologies which were good have become flawed.
Okay. Okay. So this is how our brain works. This is trapped prior. Yeah. So trapped prior never going to change. But why why does our brain work like this? What really happens is that you know from earlier episodes you know that our brain is two parts. system one which is the instinctive part which is also handling all the uh neural processing and all of that. One of our earliest episodes we were quite young back then. Yeah. And system two is the logical thinking brain which has the beliefs, right? System two tells system one what to pay attention to. Okay. It was the other way around in the episode. So in general system one is in control and it
tells system two what to think. But in terms of collecting evidence, sometimes it goes the other direction, right? There's a very famous video clip of people playing basketball and you are told to count the number of time the ball is bounced or something like that, right? And our system two tells our system one to really pay attention to the basketball and because of that, our system one completely misses something very very important. Right? That's a lovely example of how our belief, what our system two has decided is important can completely change what we see, what we pay attention to, it changes what our senses are taking in. It changes the nature of evidence. Right? You know,
given all of these examples that you've mentioned, the research paper on capital punishments, this basketball counting, passes counting example, I am I'm now beginning to think that this entire believing is seeing is very dangerous in the context of politics. Oh, absolutely right. Politics is full of trapped prior. And I'm going to repeat an example that we used in the previous episode about American politics. Okay, just look at this chart. Americans were asked how the economy is doing. Okay? And you can see during Trump, Republicans thought economy was doing great. Democrats thought it was doing terrible. As soon as Biden became president, it flipped. You don't have to know anything else to know that this is a trapped
prior. They are not looking at evidence. They are just looking at is our person in power then all is good. if their person is power then all is bad right and this is such a lovely example that's why I have repeated it in two episodes in a row but there is much much more right that just happens all the time uh another variation on this in politics is that what people politicians do is that they invoke your priors without explicitly mentioning it okay and that is called a dog whistle for example when Elon Musk does is lots half the people believe that this is a dog whistle intended to bring out a whole bunch of
priors in his followers and the other half believe something else. I I can't believe he actually did that. Like I'm okay. If you have other examples of dog whistles, post them in the comments. Right. Dog whistles are there in politics all the time. This is not just a dog whistle. It is something way worse. But yeah, it is also a dog whistle. Yeah, it is a dog whistle. All dog whistles are waver. So they are they definitely are. So uh the net summary of this episode is that facts don't care about your feelings. Actually more like feelings don't care about your facts, bro. Yeah, exactly. So the most important thing to remember is to understand that your priors change how
you interpret the evidence, right? They change what you see and what you don't see. Which parts you say, "Oh, this is reliable." And which parts you say, "Obviously, the evidence is flawed." Right? And as a result, your prior can get trapped, which means now for the rest of your life, this belief is never going to change no matter how much evidence collects against it in the outside world. Right? So, can you never escape a trapped prior? Well, you can, right? So one thing that you can try for fixing a trap prior is meditation.
Vipashana works, right? Or you could try LSD, right? That has the effect of just clearing out a whole bunch of priors in your brain. I have no idea what he ate for lunch, but I have a feeling that LSD might have been involved some meditation LSD for escaping trap triers. Yes, I'll put a link of a psychiatrist saying this in the description. Thank you. I thought he was going to put a normal people for normal people I would say that try to find trusted third parties who can point out to you that your priors are trapped.
Right? So try to find people uh who do actually change their views. All right? So a BJP supporter who once in a while does say antiBBJP things or a anti-BJP person who once in a while says proBJP things. That's what you want to look out for. Yeah. And also there is a subreddit called change my view uh which does a lot of interesting debates on uh topics that people want their views changed on. Frequent it once in a while read through it with absolute uh uh non prior non-trapped triers if you can. It actually takes active participation to change a trap trier. I think yeah I mean you have to have an open mind. Keep
asking yourself what if this is true right? What if those guys are right and I am wrong? What if this is a trapped prior? Yes. A lot of things in my life while I was discussing this episode with Naven have turned out to be some sort of trapped prior which I have to work on and I'm sure you also must have thought of several trap priors as you were watching this. Share it with us if you think you can share it with us. Else share this episode with others so they can find their trapped priors. Meanwhile trapped in this studio, Shri Kant Naven Future IQ.