Video Transcript: Thinking, Fast and Slow

Hi, I'm David Feddes and this talk is about Thinking Fast and Slow. Let's start out with a little  bit of fun. If you have a pen and paper handy, just get ready to write down some answers.  First question, how many animals of each kind did Moses take on the ark? Second question, a  ball and bat together cost $1.10. The Bat costs $1 More than the ball, how much does the ball cost? Is that your answer. In a textile factory, five machines take exactly five minutes to make five shirts. How many minutes? Will it take for 100 machines to make 100 shirts? Write down  your answer. And finally, a pond has water lilies. Each day, the flowers double the area they  cover. If it takes 48 days for the pond to be completely covered, how many days would it take  to be half covered? You have your answer to that one. Okay, let's look at the answers in  reverse order of the questions. It would take 47 days for the pond to be half covered. Because if it doubles every day, then if it's half covered on day 47 It's completely covered on day 48.  The easy answer, which most people answer is 24. But the right answer is 47. In a textile  factory five machines take exactly five minutes to make five shirts. So how many minutes?  Will it take for 100 machines to make 100 shirts will the easy answer is 100 The right answer  is five. Because each machine takes five minutes to make a shirt. So 100 machines will make  100 shirts in five minutes. A ball and bat together cost $1.10 The Bat costs $1 More than the  ball how much does the ball cost? Well, the easy answer is 10 cents, the right answer is five  cents. Because if you said 10 cents, then the bat costs $1 More than that. So the bag would  cost $1.10. And the two together would cost $1.20. The right answer is five cents. But if you  got it wrong, you're in pretty good company. 80% of college students said 10 cents. And more  than 50% of students at elite universities like MIT, Harvard and Princeton, said 10 cents. So if  you made a mistake, you're not the only one. The people who made those mistakes, were  plenty smart to get the right answer. But they didn't check their answer to make sure that it  all added up and was correct. How many animals of each kind of Moses take on the ark?  None. Noah, not Moses, was on the ark? Well, then let's ask the question a little differently.  How many animals of each kind did Noah take on the ark? He took seven pairs of each kind of clean animal and one pair of each kind of unclean animal. So if you said he took one pair or  two of every kind, then you weren't quite right. But again, the instant answer is a pair of each  animal because that's what it looks like in the pictures of Noah's ark that you've seen,  painted, or in the Bible stories that you've heard. It's always two by two except the Bible  actually says in Genesis seven, verse two, that seven pairs of each kind of clean animal and  one pair of each kind of unclean animal went on to the ark. Again, the obvious answer is the  one based on what you saw in a picture somewhere, or what you're heard of the Sunday  School Story somewhere, but not the actual answer. If you dig into the details of the Bible,  thinking fast, gives you one answer. Thinking slow and digging in a little deeper, gives you a  rather different answer. Here's an easy logic question. All roses are flowers. Some flowers fade quickly. Therefore some roses fade quickly. Is this argument logically valid? No, it's not valid.  Perhaps no roses are among the flowers that fade quickly. We only know that some flowers  fade quickly, but maybe all the ones that fade quickly. don't happen to be roses. So we have  to slow down and check the logic Thinking Fast and Slow. That's the title of a book by Daniel  Kahneman. Daniel Kahneman is one of the most influential cognitive psychologists in the  world and Kahneman won the Nobel Prize actually in economics for his work on decision  making. But he is a teacher or at least is a teacher emeritus at Princeton University. In  psychology, one of the most popular books that he wrote is Thinking Fast and Slow. Very, very influential book. Think fast. you look at this face. And instantly you know how she feels. You  know, she's happy. If she said something, you know that it would be something cheerful. Just  know that instantly. What is 17 times 23? Unless you're really a math whiz, you don't know  that answer instantly, do you? You got to think about it, you may even have to work it out.  And if you work it out, and you say, well, three times 17 is 51. Two times 17 is 34. Put them in  the right column, add 51 and 340. You get 391. You figured out the answer, if you know how  to do multiplication, but it didn't pop into your head. The instant you saw it the way looking at a smiling face told you how a person was feeling and predicted what she might say, or at  least the cheerfulness, of what she might say. Kahneman and other psychologists speak of  two systems, they use it as kind of a figure of speech, they know that the human mind is not  just automatically and totally divided into two systems. But it's useful to think about it this 

way. System one is fast, instant, involuntary, automatic, effortless, it just happens to you, you  immediately jump to conclusions through system one, system two, is slow, deliberate,  attentive, you have to focus effortful, you have to put some work into it. Here are some  samples, system one, you can see one thing is closer than another, you have instant depth  perception. When you see a face of a person, you know, you instantly recognize that person.  When you sense anger in someone's voice, you don't do computations about frequencies of  the voice sound or something you just know, if it sounded angry. One plus one is two, you just know that instantly. When you're driving a car down the road without traffic, sometimes  you're hardly paying attention, but you're turning the wheel properly, you're responding  you're staying, you're following the lane when you need to. But you're doing it almost on  autopilot. You understand a simple sentence The moment you hear it, these are all samples of system one the automatic, instantaneous recognition or sense of knowing system two is a  little different. When you're looking for someone at an airport, you don't instantly recognize  you're looking at a lot of different faces, you're putting effort into figuring out where someone  is. Or if you're looking for a certain kind of person wearing a white hat, for instance, you're  scanning and you're looking, you're taking a test and you're trying to recall information. Your  mind is trying to retrieve something from memory or figure something out. You're in a social  setting, and you feel like yawning. Oh, this is boring would you please be quiet. But you're a  polite person. And you control your manners in a social setting. And you look and you smile  and nod and try to act interested. You're making an effort, your system two is making an  effort to overcome what system one really feels like doing. When you're deciding on a plan of  action. System two is slowly and deliberately looking through some options and some factors  before reaching a conclusion. System two evaluates complex logical arguments. You don't  instantly know based on intuition, whether an argument is logically sound or not. You have to  look at it and think it through or when you're putting together an argument. It takes a lot of  focus and effort. When you're pondering how the Bible applies to your situation. Now, you  have to give some thought to it. What's the Bible saying? What's the situation? What are the  links that might be in common between the Bible and the current situation? And how does it  apply? It's not just an instant intuition. But much of the time it's something you have to think  through very cautiously and carefully. So you have these two systems says Kahneman and  system one has impressions, just immediate impressions, intuitions, intentions, feelings,  desires, and those aren't things that you're controlling or that are developing slowly but they  they instantly come to you system two usually believes system one's impressions, and it  usually acts on system one's desires. System two takes over if system one is surprised, or if  system one is stumped. But often your reactions are just instant based on intuition or your  feeling or your impression in that moment. But then system two will kick in if something came along that you weren't expecting. Or if you have to figure out something that isn't instantly  obvious. So system one is fast thinking system two is thinking slowly. Which horizontal line is  longer? You look at it and it's immediately obvious. The lower line segment is the longer one.  When you measure them, however, you find that those two line segments are exactly the  same length. This is called the Muller-Lyer. Illusion. And once you've seen it measured, then  your system two knows, the bottom line still looks longer to system one. But now that you've  put in more effort, and system two has done the actual measuring, you know that the lines  are equal, but even knowing they're equal, that bottom line still looks longer. Now system  one, your automatic reaction of your mind and system two your attentive thinking, work well  together, much of the time system one will save you a lot of time and energy. If you had to  ponder every belief and every decision, it would be very slow and very exhausting to make  your way through life because you're making decisions. You're having impressions, you're  doing stuff all the time. And it's great that you have system one to take care of a lot of stuff  instantly and automatically. And then you have system two there to evaluate the input from  system one as it's needed. But beware of biases, system one has some built in biases. And it  tends towards systemic, frequently repeated errors in certain kinds of situations. A lot of the  time, it works great. But there are certain kinds of situations where it makes the same kind of  typical mistakes over and over again. And we're going to be looking at some of those in other  talks. System two is sometimes blind to the biases of system one. And it accepts its errors 

rather than finding the errors and fixing the errors. So even though you have the system two,  it doesn't always do its job. It's not always looking for the biases. And it's not always fixing the errors that have been made. Sometimes it's good to jump to conclusions. jumping to  conclusions is efficient, says Daniel Kahneman, if the conclusions are likely to be correct, and  if the costs of an occasional mistake are acceptable, and if the jump saves much time and  effort. So system one's fast thinking is often right, and it's efficient. jumping to conclusions is  risky. When the situation is unfamiliar, the stakes are high, and there's no time to collect more information. In such situations, intuitive errors are more likely. And these errors may be  prevented by the deliberate intervention of system one of thinking more slowly and carefully  and intentionally. So do you use your intuition and just go with it? Or do you reason more  carefully? Do you think faster, think more slowly. If a belief or a decision is minor, go with  intuition. Don't think too hard. If a belief or a decision could have important long term impact,  put time and effort into hard thinking. And you need to train your thinking skills so that  system two can work well when needed. That's one of the purposes of studying logic and  critical thinking is so that your system two becomes more alert and more skilled when it  needs to correct the input of intuition. And of the fast thinking of system one. System two has  a job but it's kind of a smug slug. It feels pretty good about itself most of the time. And it's  kind of lazy most of the time system two feels in charge. But says Kahneman it's lazy, and it  prefers minimum effort. Some thoughts and actions that system two believes that it rationally chose through hard thinking, were actually prompted by system one and system two didn't  even know it. And let's face it quick, easy answers just plain feel right. And when something  feels right, we don't look at it very carefully to find out whether it really is right. So very often  system two can be kind of a smug slug that just takes what's fed into it by intuition and  feeling and intention without examining it. And I just want to say, don't be a slug. Think  harder. When you think about logic and critical thinking there may be times when you say oh  man, this is tiring. I don't feel like doing this anymore. Oh, sorry. But please Think harder.  There may be times when you say this is dumb. I already know how to think plenty well, don't  be so smug. Think humbler. Think harder, think humbler? And then you'll get a better balance  of your fast thinking and your slow thinking and are better able to grasp the truth. I hope that  as we continue to think about the way our mind works, to think not only about cognitive  psychology, but then about how actual logic and critical thinking work, that you'll be able to  think harder to think humbler to think better.