I read Malcolm Gladwell’s Blink a few years ago and my impression was that he had observed an interesting phenomenon but he had not discovered the underlying reason for the “Blink effect.” In this document I want to give my analysis of the Blink effect.
Summary of Blink: There are many cases where an instant decision, made within seconds, is nearly as good, and sometime better, than decisions made more deliberately and rationally with a lot of thought and analysis. By understanding how these “snap judgments” are made and when to trust them and when not to, you can improve your decision-making.
The first story in the book is about the kouros (a type of statue) that the J. Paul Getty museum was thinking about buying. They performed several tests and analyses and had determined that it seemed genuine. Then they brought in several art experts to look at it and they all felt uneasy about it and thought there was a good chance it was a fake. It was later shown to be a fake.
The book discusses several cases where a quick (within two seconds), intuitive decision is more reliable and then more lengthy decision process. Some examples are:
- the Getty kouros
- Deciding whether a couple will stay together by examining their interactions for just a few minutes
- Deciding whether you will like a professor by matching him or her teach for just a few minutes
Gladwell calls this process “thin slicing”, looking at tiny parts of the world for the information to make a decision. He notes that these decisions processes take place behind a “locked door”, that is, in the unconscious part of the brain, and that even the people making the decisions do not understand how they are making the decisions.
Gladwell talks about how sometimes too much information can hurt a decision process rather than help it. We are overwhelmed with the data and tend to cherry-pick it to support our initial decision. A long decision process can be too predictable and not good for finding unusual solutions.
Sometimes these quick decisions are not good, when they are based on prejudices and preconceptions. Also we are often prey to salesmen who can manipulate us to make bad decisions. Another case where first impressions can be faulty is in things that you have to live with a long time and you become expert with. Beginner behavior is unlike expert behavior.
Gladwell’s conclusions are that fast, intuitive decision making can often be better and we should not underestimate its power or denigrate it as not logical. It is important to understand which situations it works in and where you need to consider both types of decision making. Gladwell does not really say why this snap decision might be better but just observes the fact and gives many examples of it.
My explanation for the Blink effect: Most decisions are an adversary relationship where someone else is trying to influence your decision. If the other person knows how your decision process works they can take steps to subvert it and cause you to make the decision in a way that is wrong for you but good for them. This is often called “gaming the system”. Instant, intuitive decisions are made unconsciously and even the person making the decision does not understand the decision process. So it is hard for someone else to subvert the decision process. On the other hand, a careful, rational decision process is often public and someone else can take steps to subvert it. The result is that the quick decision is better since it is not manipulated.
Gladwell’s kouros example: Gladwell opens Blink with the example of the Getty museums kouros (a statue). In brief, they had a statue and they were trying to decide if it was genuine. They performs many of the standard tests and the statue appeared to be genuine. But one art expect took a look at it and decided instantly that it was a fake. Eventually it was shown to be a very clever fake.
How does my analysis apply here? The rational, lengthy procedures for detecting fake statues are well known in the art world. Someone producing a fake will know exactly what tests will be performed. So the faker knows where to spend time in constructing the fake, in those places where it will be tested. If the forger is very skilled then he will produce a very good fake that passes the standard tests.
An art expert has probably seen thousands of statues and hundreds of fakes. Over the years the expect develops a feeling for which are genuine and which are fake. This feeling is intuitive and even the expert does not really know how the decision is made. In the Getty example, the expect could not say exactly what made him think the statue was a fake. There probably is an unconscious decision process going on that looks for certain clues. But since the decision process is not generally know and the clues that it uses are not known, even to the expert, the faker does not know how to make sure his fake passes the intuitiion test. In other words, you cannot game the system if you do not know how the system works.
Testing knowledge: Tests provide a particularly clear example of how one would game a system. Let’s take a very simplified example to illustrate the idea. Suppose we have a class where you are supposed to learn 10,000 facts. The final exam consists of 100 questions, each asking about one of the 10,000 facts. The 100 questions are chosen randomly from the 10,000 facts. If you get 90 correct then we infer that you know 90% of the material, that is, you know about 9,000 of the 10,000 facts. Pretty much all tests work roughly like this. If someone can determine ahead of time which 100 questions will be asked, for example by stealing a copy of the test before it is given, then that person can just memorize those 100 facts and get 100%. We then assume that they know all of the facts when they really know only 1% of the facts.
The test relies on several related assumptions: that the questions are randomly chosen, that the test-taker does not know in advance which questions will be asked, that the knowledge of the test taker is uniformly distributed among the facts, etc. The cheater games the system by invalidating one or more of the assumptions that make the test work, in our example, the assumption that the test-takes does not know the questions in advance.
Decision making processes: A decision making process is a procedure that involves a series of data points. The decision maker then goes through an algorithm that uses the values of these data points and come out with a decision, maybe a number or maybe a yes or no decision.
In the testing knowledge example, the data points are the answers to the 100 questions, in particular, whether they are right or wrong. The decision procedure produces a numerical score between 0 and 100 which estimates the percentage of the 10,000 facts the tester knows.
In the example of the kouros it consists of the results of several scientific tests of the composition of the statue, the extent of the weathering of the stone, etc. The algorithm is that it must meet some minimum standard on all the tests to be considered genuine.
Sampling: Almost all decision making processes involve sampling. They do not test everything but just take samples that are considered representative of the whole. If the samples pass a test, it is assumed everything else like it would also pass the test.
This is where the decision making process is vulnerable to gaming. If someone knows what samples will be taken then he can make sure it passes the test at those places but not others.
The Blink effect: So the reason for the Blink effect is that quick, intuitive decision processes are hard to game and so remain valid even in the face of an opponent who is trying to subvert the validity of the decision. It is not the fact that they are quick that is important, it is the fact that the decision procedure in unknown. The data points sampled are not known and the algorithm for making the decision from the data points is not known.
So we can get the same effect with a longer, more rational decision process if we take care to prevent the system from being gamed. Of course, saying that does not mean that this is possible, in many cases it might not be.
Blink effect failures: But the quick decision processes are not immune from being gamed, as Gladwell points out in his book. The art fake example is hard to game because it is uncommon and exists in a small world of art expects. And, even though some of this art is valuable, it is not worth the effort to figure out how to game it.
Trust: Where is it worth it to learn how to game quick, intuitive decisions? All the examples come down to one area: trust and selling things. A salesman wants to convince you to buy his product. He wants you to trust him and the representations he makes about the product. It is notoriously hard to know who to trust, who to believe. It is very profitable to be able to lie convincingly and so humans have studied the problem extensively over many thousands of years. Good salesmen have many tricks to get you to trust them. Basically they have figured out some parts of the internal, intuitive decision process that people use to decide who to trust.
People are very bad at knowing who to trust. They are fooled all the time. The problem, in the terms we have been using here, is that people have learned how to game the decision making process that people use to decide who to trust. People use a sampling process to decide trust because it is not possible to look inside someone’s brain and really know what they are thinking. Other people have learned what those sample points are and use them to fool people.
The only real defense is to make the cost of fooling the decision process higher than the value of defeating it. This is the approach of all security, complete security is not possible but it is possible to make it very expensive to defeat a security system. In the case of trust, the tried and true method is to trust people you have known a long time. If you have known someone 10 years and they have been trustworthy then it is usually safe to assume that they will remain trustworthy. This method has two problems. First, it is not foolproof. Conditions can change and someone can be trustworthy for 10 years and they betray you. Second, it is very expensive. It only allows you to trust someone you have known for a long time. How do you buy something on a trip?
Generalization: It is my belief that one of the major problems that we face is people trying to game our systems. Of course, we have had this problem with trust for thousands of years. People are always trying to convince us of things and trying to subvert our decision making processes in order to convince us of something contrary to our own interests.