Reviewing Thinking Fast and Slow – 7 Psychological Fallacies That Affect Our Relationship With Money (and everything else)

Many well-regarded personal finance and investing books, The Psychology of Money by Morgan Housel being a stand out example, have taken special care to address the matter of psychology in money management. For all its remarkable capacity for reason and logic, the human mind is riddled with irrationality. Daniel Kahneman, author of Thinking Fast and Slow, approaches psychology from a broader perspective, examining the psychology of decision making in all facets of life. Is Thinking Fast and Slow a genuinely enlightening read for those of us on the path to FIRE? Or should we set it aside in favor of more specialized books?

The long and short of it:

In Thinking Fast and Slow, Kahneman presents readers with an array of psychological concepts and theories about how and why we make the decisions that we do. Kahneman presents a set of foundational principles alongside a variety of more specific theories and experiments which serve as examples.

System 1 vs System 2

There are two modes of operation for the human brain. The first is System 1: our unconscious intuitive self, it’s fast, instinctive, and constantly active. The second is System 2: our conscious thinking self, it’s rational, deliberative, and only active when directly called upon. System 2 is slow and lazy, it leaves the decision making to System 1 at every possible opportunity. Meanwhile, System 1 is reckless and brash, making snap decisions based on rapid free-association as opposed to solid evidence and logic.

Due to the indolence of System 2 and the rapid-fire confidence of System 1, a whole host of psychological pitfalls result:

1. Anchoring

The anchoring effect is the tendency for a given number to affect people’s estimation of an unknown value, regardless of whether the given number resulted from a dice throw or in-depth calculation.
Kahneman and his research partner Amos Tversky rigged a wheel of fortune to only land on 10 or 65.

Then they invited university students in for an experiment. First, they spin the wheel, then had the student write down the number it landed on. Afterwards, Kahneman and Tversky asked the students “Is the percentage of African nations among UN members larger or smaller than the number you just wrote? What is your best guess of the percentage of African nations in the UN?” Students know that the number was produced by random, the written number should not have any influence on the students’ estimation of African nations in the UN. Yet on average, those students who got 10 estimated 25% while those who got 65 estimated 45%.

In the instance of estimating the intrinsic value of a stock, we are similarly persuaded. The given number (stock price) will inevitably influence our estimation of the stock’s true worth unless we’re exceedingly wary. It’s for this reason that overpriced stocks look attractive while underpriced stocks look risky. Despite the fact that we should not let the actual price of a stock influence our calculation of its intrinsic value, most of us can’t help but do so due to the anchoring effect. For example, imagine you have a normal plastic bag. If asked, we might say it’s worth a nickel at most. However, if the store priced the plastic bag at $1000 and hundreds of people purchased it for that price, we might be persuaded that the plastic bag is worth more when it’s not.

2. Overconfidence

System 1 is unconscious and therefore it isn’t able to second-guess and self-evaluate its judgements. Paired with a lazy System 2, it’s only too easy for people to form beliefs that lack evidence. Confidence, contrary to what our intuition says, is not an indication of correctness. In fact, the more confident we are, the more vigilant we should be. In the case of investing, it’s important not to be led astray by overconfidence, both your own and that of investing professionals.

Given the danger and prevalence of overconfidence, Kahneman offers us a thought experiment called the postmortem to help diminish the tendency. Postmortem is where you imagine that the project you’re about to embark upon or the business you’re about to invest in had failed 15 years down the line. You then take 5-10 minutes to brainstorm how this might have happened. In performing this exercise, you inoculate yourself against overconfidence and create opportunities to pre-empt future mistakes.

3. Base Rate Neglect

To illustrate this concept, Kahneman came up with the following thought experiment:

Tom W is a graduate student at the main university in your state. Please rank the following nine fields of graduate specialization in order of the likelihood that Tom W is currently studying in each field. Use 1 for the most likely, 9 for the least likely.

• • business administration
  • computer science
  • engineering
  • humanities and education
  • law
  • medicine
  • library science
  • physical and life sciences
  • social science and social work

Going by pure statistics, we would guess that Tom W is more likely to be a humanities and education student than a computer science or library science student. This is a base rate, because the sheer percentage of students who graduate with a humanities or education degree definitively outnumbers the number of students who graduate with a computer science or library science degree. However, consider how your judgment changes when you read the following:

The following is a personality sketch of Tom W written during Tom’s senior year in high school by a psychologist on the basis of psychological tests of uncertain validity:

Tom W is of high intelligence, although lacking in true creativity. He has a need for order and clarity, and for neat and tidy systems in which every detail finds its appropriate place. His writing is rather dull and mechanical, occasionally enlivened by somewhat corny puns and flashes of imagination of the sci-fi type. He has a strong drive for competence. He seems to have little feeling and little sympathy for other people, and does not enjoy interacting with others. Self-centered, he nonetheless has a deep moral compass.

Most people would at this point be persuaded to re-evaluate Tom W’s graduate specialization. Surely, he’s more likely to be a computer science student than a humanities and education student, if he liked sci-fi and disliked human interaction? Nevermind that this is a high school personality sketch of uncertain validity. System 1 likes narratives and stereotypes. The description of Tom W is overwhelmingly in line with computer science, enough for most people to entirely forget about the base rate and statistical likelihood that tells us he is very likely to be a humanities or education student even with the personality sketch.

Humans and Econs

One of the base assumptions of economics is that the economy is made up of rational agents, all making rational and internally consistent decisions based on all available information. Kahneman takes issue with this, asserting that a Human is far more prone to errors of logic and judgment than an Econ. The main differences between Humans and Econs can be observed in the following situations:

4. Loss Aversion

At the core of many of our poor money choices lie loss aversion. The idea is that most people feel the loss of something far more acutely than they feel the gain. Through his research, Kaneman found that the ratio of loss aversion measures out to 1:2 or 1:1.5 on average. This means you must earn $200-$150 to offset the psychological pain of losing $100.

Although it’s reasonable to protect wealth more fiercely than pursue gains, many people are loss averse to the point of irrationality. When faced with an offer of —

              pay $400 for 95% chance to win $1,000 

                        OR 

               pay $700 to win $1,000 for sure 

Most of us would go with the second option. Objectively speaking, 95% chance to win $600 is an excellent deal, yet we are willing to pay a hefty premium to eliminate the negligible chance of losing money.

To resolve this in-equivalency Kahneman recommends taking a broadview perspective when investing. Our stock performance is not determined by short-term dips. Waiting until we come upon an opportunity that offers 100% guarantee to make money means we’ll never invest at all. It may also mean we end up relying solely on bank deposits with returns that fail to keep up with inflation, an inevitable result of loss. Yes, it’s likely that some investments will come out at a loss, but as long as you make more good investments than bad, your net result will follow the trend of probability. Meanwhile, if you shy away from good deals, these missed opportunities will gradually accumulate into a big loss.

5. Attitude to Risk

In Kahneman and Tversky’s Nobel Prize-winning theory called Prospect Theory, they posited that just as there are diminishing returns for gains, there is a similarly diminishing impact for losses.

Kahneman offers two illustrative problems to explain prospect theory:
    Problem 1*: Which do you choose?*
    Get $900 for sure OR 90% chance to get $1,000
    Problem 2*: Which do you choose?*
    Lose $900 for sure OR 90% chance to lose $1,000

As mentioned in the previous point on Loss Aversion, most people would much prefer to get $900 for sure for Problem 1. What’s interesting is that this situation is entirely inverted in Problem 2. All of a sudden, people would prefer a 90% chance to lose $1,000 over a guaranteed loss of $900.

The reason is because going from $900 to $1,000 is an insignificant increase in psychological value and the 10% risk of getting nothing at all is a huge loss. We are unwilling to put $900 on the line for a chance to gain an additional $100, even when the odds of success is 90%. When it comes to gains, we are risk averse.

Meanwhile, going from a sure loss of $900 to a potential loss of $1,000 is precisely the opposite. If we are guaranteed to lose $900, the loss of an additional $100 feels negligible. In exchange for the possibility of losing an additional $100, we gain a 10% chance to lose nothing at all, which has much greater psychological value. When it comes to losses, we are risk seeking.

Why is this important?

Consider we purchased a stock for $80 a share and it has gone down to $30. We know the company is performing poorly and the economy is entering a recession. The odds that the stock will drop to $20 and stay at that price is 90%. The smart decision is to sell the stock at $30 and reinvest in another stronger company, but because we are risk seeking when faced with loss, we hold on to the stock for that slim 10% chance that it will bounce back to $80 a share. This is the reason why we hold on to losing stocks and refuse to realize a loss. Selling now and losing $50 for sure feels much worse than a 90% chance to lose an additional $10 and a 10% chance to make it all back.

6. Statistical Blindness

To illustrate this, Kahneman provides a personal anecdote. Years ago, Kahneman worked with a team of educators to design a curriculum and write a textbook for a high school class on judgment and decision making. During an early brainstorming session, Kahneman and his team each shared their estimates for how long they think the project will take. Guesses ranged from 1.5 to 2.5 years. When the dean of the Hebrew University’s School of Education, warned that other teams working on the sae project took about 8-10 years and that 40% never finished, Kahneman dismissed this information. 

In truth, Kahneman now recalls, they should have quit right then and there. No one was prepared to devote so much of their time to a project with such a high chance of failure. Eventually, the textbook and curriculum was completed; the project took a total of 8 years.

The tendency of the individual is to assume that statistics do not apply to them. We may know intellectually that we are influenced by the bystander effect and therefore less likely to help someone in danger when we’re surrounded by others, but emotionally we’re convinced that we won’t be one of those bystanders. We may know that the new IPO stock we purchased is very, very unlikely to become the next google (or even turn a profit in the next quarter), but we can’t help but wonder what if…?

What makes Thinking Fast and Slow unique?

Seeing as it’s a book about the psychology of decision making written by the foremost expert in the field, you can imagine that Thinking Fast and Slow has powerful applications. Governments can (and do) implement policies in accordance with these principles. CEOs can (and do) apply these principles to maximize profits. You can (and should) incorporate these principles when making important decisions in your daily life.

While Daniel Kahneman’s book speaks for itself, there’s no ignoring his remarkable accomplishments. Kahneman is credited as one of the founders of behavioral economics, the recipient of the Nobel Prize in Economics in 2002 and Professor of Psychology and Public Affairs Emeritus at Princeton. Just as it would be wise to consider Warren Buffett’s philosophy before becoming a serious investor, it would be wise to account for Daniel Kahneman’s research before becoming a serious decision maker.

Final thoughts:

This review has examined only a fraction of the many psychological phenomena detailed in Thinking Fast and Slow. There was a deliberate prioritization of the psychological factors most relevant to personal finance and investing, but we must recall that FIRE is about more than personal finance, it’s a lifestyle. In order to achieve FIRE, it’s important to take a step back and return to the fundamentals of decision making. Why do we think about the things we do? And how can we change this so it better aligns with our values?

Should you read Thinking Fast and Slow?

Absolutely.

For some readers, I don’t doubt that the theories Kahneman begins with will seem pedestrian. The verbiage of System 1 and System 2, the concept of priming, availability heuristic, loss aversion — these are all relatively familiar. If you are among this group of less easily impressed, Kahneman offers a more complex and mathematical approach in later chapters, for example prospect theory, base rate neglect, and regression to the mean. Additionally, just because we’re aware of psychological pitfalls doesn’t mean we’re immune, so it does us good to get a refresher every now and then.

I should warn you though, that at 499 pages, Thinking Fast and Slow is not a short book. Not to mention it’s decently dense, especially later on. It’s all in all an enjoyable read, but there are a few moments, particularly in the later chapters, where the language becomes difficult to parse. My recommendation is to go slow and take it easy. Thinking Fast and Slow is a book to be digested, not consumed.