You may not realize it but your brain actually processes information in two very distinct ways. Like when you look at this photo, you instantly know she has blond hair, is visibly angry, and likely has some choice words to yell. Without any effort you experience fast thinking, but if you look at the following problem something different happens. Sure, you immediately know it’s a multiplication problem, and you knew you could solve it if you had the energy but didn’t. If you do try, your muscles will tense and your pupils will dilate and you heart rate will increase. Now, you’ve experienced slow thinking. These two systems of fast and slow thinking, dictate much of our perception and reaction in life. Take these lines for example, it’s clear that they’re different lengths, but if you measure them, they’re actually the exact same length. Even now that you know, system 1 or your fast thinking, can’t stop seeing the illusion because it acts automatically. Similar effect to seeing here, which figure’s the largest? Again, they’re all the same size, but the suggestion of perspective in depth causes your system 1 to interpret the picture as three-dimensional, even though it’s on a flat two-dimensional surface. It’s making quick work of the available information, and so your conscious system 2 or slow thinking must compensate after the fact and choose not believe your intuition or instinct. Wanna see your system 2 in action? We’ll show you a string of four digits, you read them out loud then add one to each of the original digits. If the card reads 3795, the correct response would be 4806. We’ll then go to the next card and you’ll do the same, followed by the next card. Ready? Go! Few people can cope with more than four digits, but even harder is add 3. The interesting bit is that though your pupils would have dilated you often become effectively blind when you fully engage system 2. Did you notice the color of the text change? Or how about the fact that the numbers completely changed when I put them off to the side? Listen to the following puzzle. A bat and a ball cost $1.10. The bat costs $1 more than the ball. How much does the ball cost? Chances are, your system 1 intuition was yelling 10 cents But this appealing system 1 answer, we know, is wrong In fact, the correct answer is 5 cents Even if you worked out the correct answer, you likely thought of 10 cents along the way System 1 is trying to work out an answer as quickly and seamlessly as possible Which is extremely beneficial in everyday life If every activity required full mental effort it would be exhausting. But, knowing this allows us to understand that not all of our first impressions are correct. How many animals of each kind did Moses take into the ark? So few people detect what is wrong with this question that it’s been dubbed the Moses illusion. In fact, Moses took no animals, Noah did. Again, our brain invests as little resources as necessary so that things run quickly and smoothly. Because Moses is not abnormal in the biblical context, System 1 unconsciously detects an association between Moses and ark and quickly accepts the question. In a similar way, System 1 generates context without you knowing. Reading each of the following may seem fairly simple ABC, Ann approached the bank, and 12 13 14 But your brain actually interpreted these ambiguous statements without you ever knowing You could have read it as A 13 C or 12 B 14 But your brain created the context unconsciously Also, you likely imagined a woman with money on her mind walking towards a building with tellers But if the sentence before this was: they were floating gently down the river. The entire scene would’ve changed because ‘Bank’ would no longer be associated with money. Without an explicit context, System 1 quickly generates one based off similar experiences In this case, you’ve likely visited more banks than rivers and so the context is resolved accordingly This ties into a context called “Priming” For example, if I said “Wash” How would you complete this word fragment? Most would see soap, but had I just shown you the word “Eat” you’d be more likely to see “Soup” In this way, both “Eat” and “wash” prime your thoughts Though system 2 likes to think that it’s in charge and knows what’s going on The truth is that priming effects even been shown to affect and modify behavior These arrive in system one and you have no conscious access to them If you’d like to learn more about the thinking system in your brain, Check out the book “Thinking Fast and Slow” by Daniel Kahneman Which covers it in great detail I’ll put the link in the description which you can check out Go a burning question you want answered? Ask it in the comments or on facebook and twitter. and subscribe for more weekly science videos.