Elementary, My Dear Watson*

When you’re trying to solve a complex problem, determine a course of action, or evaluate others’ conclusions, you’ll need to engage logical System 2 reasoning, which is the opposite of System 1’s quick assessments.

I never guess. It is a shocking habit—destructive to the logical faculty. —Sherlock Holmes in The Sign of Four

It can be helpful to understand different types of reasoning, be able to identify the type—or types—of reasoning that are being applied in a given situation, and know how accurate each type is likely to be.

But recognizing and/or applying a reasoning process to your problem or evaluation process isn’t enough to guarantee that the outcome of that reasoning process will be sound or accurate. Skillful reasoning doesn’t compensate for faulty premises or missing or biased information.

The following descriptions (but not the examples) of deductive, inductive, and abductive reasoning were provided by Alina Bradford, writing in Live Science (livescience.com).

Deductive reasoning: conclusion guaranteed

Deductive reasoning is a basic form of valid reasoning. Deductive reasoning, or deduction, starts out with a general statement, or hypothesis, and examines the possibilities  to reach a specific, logical conclusion, according to the University of California. The scientific method uses deduction to test hypotheses and theories. “In deductive inference, we hold a theory and based on it we make a prediction of its consequences. That is, we predict what the observations should be if the theory were correct.  We go from the general—the theory—to the specific—the observations,” said Dr. Sylvia Wassertheil-Smoller, a researcher and professor emerita at Albert Einstein College of Medicine.

In deductive reasoning, if something is true of a class of things in general, it is also true for all members of that class. For example, “All men are mortal. Harold is a man. Therefore, Harold is mortal.” For deductive reasoning to be sound, the hypothesis must be correct. It is assumed that the premises, “All men are mortal” and “Harold is a man” are true. Therefore, the conclusion is logical and true.


  • It is dangerous to drive on icy streets. The streets are icy now so it is dangerous to drive now.
  • All birds have feathers and robins are birds, so robins have feathers.
  • Elephants have cells in their bodies and all cells have DNA, so elephants have DNA.

[Caveat: Deductive inference conclusions are certain provided the premises are true. It’s possible to come to a logical conclusion even if the generalization is not true. If the generalization is wrong, the conclusion may be logical, but it may also be untrue. For example, the argument, “All bald men are grandfathers. Harold is bald. Therefore, Harold is a grandfather,” is valid logically but it is untrue because the original statement is false.]

Inductive reasoning: conclusion merely likely

Inductive reasoning is the opposite of deductive reasoning. Inductive reasoning makes broad generalizations from specific observations. “In inductive inference, we go from the specific to the general. We make many observations, discern a pattern, make a generalization, and infer an explanation or a theory,” Wassertheil-Smoller told Live Science. “In science there is a constant interplay between inductive inference (based on observations) and deductive inference (based on theory), until we get closer and closer to the ‘truth,’ which we can only approach but not ascertain with complete certainty.”

Even if all of the premises are true in a statement, inductive reasoning allows for the conclusion to be false. Here’s an example: “Harold is a grandfather. Harold is bald. Therefore, all grandfathers are bald.” The conclusion does not follow logically from the statements.


  • John is a financial analyst. Individuals with professions in finance are very serious people. John is a very serious person.
  • Jennifer leaves for school at 7:00 a.m. and is on time. Jennifer assumes, then, that she will always be on time if she leaves at 7:00 a.m.
  • The water at the beach has always been about 75 degrees in July. It is July. The water will be about 75 degrees.
Abductive reasoning: taking your best shot

Another form of scientific reasoning that doesn’t fit in with inductive or deductive reasoning is abductive. Abductive reasoning usually starts with an incomplete set of observations and proceeds to the likeliest possible explanation for the group of observations (Critical Thinking Skills, Butte College). It is based on making and testing hypotheses using the best information available. It often entails making an educated guess after observing a phenomenon for which there is no clear explanation.

Abductive reasoning is useful for forming hypotheses to be tested. Abductive reasoning is often used by doctors who make a diagnosis based on test results and by jurors who make decisions based on the evidence presented to them.


  • Given a particular set of symptoms, a medical doctor needs to determine the diagnosis that would best explain most of them.
  • Jurors have to decide whether the prosecution or the defense has the best explanation to cover all the points of evidence although additional evidence may exist that was not admitted in the case.

While using one of these three types of reasoning is a function of System 2 (conscious) cognition, evaluating them—and their results—is an example of metacognition, which is a higher order of System 2 cognition. Metacognition is a skill you can develop to help you think smarter and improve outcomes in all areas of your life.

I cannot live without brain-work. What else is there to live for? —Sherlock Holmes in The Sign of Four

*This quintessential Sherlock Holmes quote was never actually uttered in any of Conan Doyle’s stories about him.

Bats, Balls, and Biases

Critical thinking is the ability to think clearly, rationally, and objectively and to understand the logical connection between ideas. It’s an active rather than a passive process. Because it requires System 2 (conscious) attention, it doesn’t come naturally to us and it isn’t easy.

In some instances, we equate difficult with boring. In fact, after reading the short paragraph above, you may already be bored. Critical thinking? Who cares and why bother?

Well, for one thing, it’s possible that improving your critical thinking skills might help you become a better person. But more importantly, it might help you get more of what you want and less of what you don’t want. That’s because good critical thinking skills are essential if you want to master the art and science of change. And unless you master the art and science of change, you’ll continue to be stuck with whatever the status quo happens to be—or to become.

On the BIAS

We all view what happens in the world and what happens to us through our own individual perspectives (our mental models). That means we are all biased.

Here’s an easy way to remember bias:

Beliefs and Values

Beliefs are ideas or principles we have come to accept as true.
Values are our personal principles or standards.
Interpretations are explanations or understanding.
Assumptions are suppositions: what we take for granted or assume.
Stereotypes are generalizations and oversimplifications.

All of these elements operate in the background (System 1) so we aren’t usually consciously aware of them. Being biased is the normal state of affairs. We don’t have to make an effort to be biased. We have to make an effort to become aware of our biases so we have a fighting chance to act in our own best interest rather than automatically.

One of the most fascinating aspects of the human condition is that we think of the conscious part of the brain (System 2) as “I.” Yet it’s the biased unconscious part of the brain (System 1) that usually runs us. It takes no time or effort to come up with a System 1 reaction or response to a situation, question, or event because System 1 is fast, vast, and always on.

As Daniel Kahneman says in Thinking, Fast and Slow:

Everybody recognizes the difference between thoughts that come to mind automatically and thoughts that you need to produce. That is the distinction.

System 1 has an answer for everything. And its answers are correct often enough to lull us into accepting them unconditionally most of the time. But you’re not going to get change from System 1; you’re going to get same old/same old.

In addition to understanding our own biases, we also need to develop the capacity to know when it’s OK to go along with System 1’s response and when it isn’t. Well-developed critical thinking skills can help us make important decisions and solve significant problems by allowing us to effectively evaluate both the information at hand and the “intuitive” suggestions spontaneously arising from System 1.

Do I need an umbrella?

If you look outside and observe rain falling, you could safely jump to the conclusion that you need to take an umbrella with you when you go outside. You would not increase your chances of making the best decision by checking the weather report on your smartphone (getting more information) or analyzing your interpretation that rain falling means you’re likely to get wet if you go out in it.

How much does the ball cost?

On the other hand, you may not want to count on the first response that comes to mind as an answer to the following question:

A bat and a ball cost $1.10.
The bat costs one dollar more than the ball.
How much does the ball cost?

If you jump to the conclusion that the ball costs 10 cents, you would be wrong—no matter how confident you might feel about your conclusion.

That’s because if the bat costs one dollar more than the ball and the ball costs 10 cents, the bat would cost $1.10 for a total of $1.20. So the correct answer is that the ball costs 5 cents and the bat costs $1.05 for a total of $1.10.

Did you do the math, so to speak, or did you jump to the quick—and erroneous—conclusion? If you jumped to the wrong conclusion, how confident did you feel about your answer? And does it make you feel any better to know that between 50% and 80% of college students also come up with the wrong answer.

Z Is for Zombie Systems

What could zombie systems (also known as alien subroutines) and blindfolded cup-stacking possibly have to do with behavior change? Quite a bit, as it turns out. But first, what exactly are these zombie systems and alien subroutines? According to David Eagleman in Incognito:

We harbor mechanical, “alien” subroutines to which we have no access and of which we have no acquaintance. Almost all of our actions—from producing speech to picking up a mug of coffee—are run by alien subroutines, also known as zombie systems.

Eagleman uses the terms interchangeably. He says the term zombie emphasizes the lack of conscious access, while alien emphasizes the foreignness of the programs.

Some alien subroutines are instinctual, while some are learned; all highly automated algorithms become inaccessible zombie programs when they are burned down into the circuitry.

Cup-Stacking Smack-Down

Cup-stacking, at least as performed by Austin Nabor, is an example of a highly automated algorithm—and thus a zombie system.

Nabor has been practicing all the moves involved in cup-stacking regularly for several years. As a result, physical changes have taken place in his brain to hard-wire cup-stacking. He can now perform it automatically without thinking about it, which is why he can do just as well when he’s blindfolded as he can when he can see what he’s doing.

In the video (link above), 10-year-old Nabor faces off against David Eagleman mano-a-mano, as it were, and hands him a resounding defeat. Eagleman said of the contest that he wasn’t even an eighth of the way through his routine when Nabor finished. During the competition, both were fitted with skull caps to monitor electrical activity in their brains. Instead of burning more energy to complete his complex cup-stacking routine speedily and flawlessly, Nabor’s brain used considerably less energy than Eagleman’s brain used to perform the routine much more slowly. In fact, Eagleman described Nabor’s brain as serene.

Eagleman’s brain burned more energy because he had to think about what he was doing and conscious thought burns more energy than zombie systems and alien subroutines burn.

When a professional baseball player connects his bat with a pitch that is traveling too fast for his conscious mind to track, he is leveraging a well-honed alien subroutine.

Your brain rewrites itself based on the things you repeatedly practice, such has hitting a ball with a bat, driving, or swimming. Some of those things could be classified as skills while others might better be classified as habits. Whether they are skills or habits, once they become “etched into the circuitry of the brain,” you lose conscious control over them. Your brain doesn’t particularly care what skills or habits (good or bad) are turned into zombie systems. The purpose of the process, as Eagleman says, is to free up resources, allowing the conscious you to attend to and absorb other tasks.

Because you lose conscious control of zombie systems and they run automatically, it’s quite difficult to change them—to put it mildly.

Learning to Ride the Backwards Bicycle

Engineer Destin Sandlin, creator of the website Smarter Every Day, was challenged to ride a bicycle that had been modified so that when you turn the handlebars to the right, the wheel turns left, and when you turn the handlebars to the left, the wheel turns right. Watch him try—and fail—to ride the bike, and then offer to pay other people if they are able to ride the bike 10 feet.

“Once you have a rigid way of thinking,” Sandlin says, “you cannot change that, even if you want to.” Riding a bicycle, for most of us, is a hard-wired zombie system. Since we don’t have conscious control over the bicycle-riding algorithm, knowing that the bicycle has been altered has no effect on our ability to modify the algorithm—at least not right away.

It took Sandlin eight months of regular practice to learn how to ride the backwards bicycle. However, he noticed that the old pathway was still there and minor distractions, such as a cell phone ringing, could cause his brain to “jump back on the old road it was more familiar with.”

Sandlin’s young son, on the other hand, who had been riding a bicycle for three years, required only two weeks to get the hang of the modified bicycle.

When Sandlin attempted to ride a normal bicycle again after having more or less mastered the backwards bicycle, he couldn’t do it at first. But after about 20 minutes, his brain slipped back into gear, and he was able to remain upright. Think about that when you’re struggling with changing a habit you’ve had for years or maybe even decades. It takes a great deal of repetition and persistence to master a replacement behavior but very little provocation to revert back to the old path.

Consciousness on the Sidelines

Having the knowledge, information, or even will to change your behavior are all System 2 (conscious) processes. They’re certainly useful and even desirable. But a habit is a System 1 (unconscious) zombie system that is not immediately responsive to your conscious intentions or attentions.

In fact, those System 2 processes can sometimes get in the way. Eagleman says:

Not only do we run alien subroutines; we also justify them. We have ways of retrospectively telling stories about our actions as though the actions were always our idea. As an example…I mentioned that thoughts come to us and we take credit for them (“I just had a great idea!), even though our brains have been chewing on a given problem for a long time and eventually served up the final product. We are constantly fabricating and telling stories about the alien processes running under the hood.

Essentially we come up with conscious explanations for unconscious systems we have no access to. When we think we understand something, but we don’t, we’re likely to also think we know what to do about it. But we don’t.

If your brain is running an alien subroutine or a zombie system you don’t want it to run, you have to make like Destin Sandlin and practice the new routine over and over and over again. And you have to be prepared to have your brain “correct” you back to your old behavior at the least provocation.

When that happens, it’s far more productive to get back up on the horse—or bicycle—than it is to create a story about it.

Part of the series A-Z: An Alphabet of Change.

Y Is for Yesses

Your unconscious shrugs off neutral or positive news or experiences, sometimes barely registering them, and hones in on the negative. You have a stronger emotional reaction to negative stimuli, which increases the likelihood you’ll remember it. Since it takes less time for negative experiences to get stored in memory, your unconscious has more negative memories to draw on than positive ones when it’s evaluating information. And negative experiences affect you longer. As Rick Hanson famously says:

Your brain is like Velcro for negative experiences and Teflon for positive ones.

That’s because your brain’s main concern is your survival, so it’s primed to detect threats. Positive things may indeed help you survive. But negative things can kill you. It’s better to be safe than sorry. It’s better to expect and prepare for a possible threat than to be surprised or ambushed by one.

It’s easy to forget you’re operating with essentially the same brain your ancestors on the savanna had—a brain that doesn’t necessarily deal effectively with the stimulation, stressors, and sheer volume of information you have to contend with in modern daily life.

The brain is, first and foremost, a survival tool, and the way that it has found to be most effective at guaranteeing survival is through the threat and reward response. Put simply, your brain will cause you to move away from threats and move toward rewards. —Dr. David Rock, author of Your Brain at Work

This may not seem particularly problematic until you realize that, in additional to actual survival needs (food, water, shelter, etc.) and actual physical threats, each of us has personalized our threat-detection system to include situations we have defined as threatening. And once your brain gets the idea that something is a threat, it responds as if it is facing a literal threat to your physical survival.

Your brain automatically looks for what isn’t working: the threats, the slights, the hurts, the things that fall apart or don’t go your way. And because the unconscious part of your brain uses associative thinking, it is all too easy to get on a negative track and stay there. One thing leads to another, or one similar thought reminds you of another similar thought, and before you know it, your mood and your attitude have soured, and your ability to refocus your attention has evaporated.

Count Your Yesses

You can’t stop your brain from noticing the negative, and it wouldn’t even be a good idea to try. But neither do you have to give in to it. The advice to count your blessings comes to mind, but I find blessings to be a loaded word on several levels. I prefer to count my yesses. It’s an effective way to turn the tide when I notice I’ve mentally starting traveling along that road to nowhere.

Although I tend to be pretty optimistic and upbeat, the first thing I noticed when I began this practice was how much easier it is to count my nos. Because the nos are brought to our attention by System 1, the part of the brain that is always on and processes 11,000,000 bits of information at a time, they come to mind immediately and automatically. Counting yesses, on the other hand, requires intention, which is a function of System 2, the conscious part of the brain that is slow, lazy, and easily depleted.

That’s why when you’re tired, stressed, or sick—or when life has dealt you some kind of blow—you simply have less System 2 attention available. It’s easy, then, for the nos to get the upper hand. I remember when I experienced a bout of food poisoning. For several days, the nos were abundant. While I observed the downward trend in my thoughts, I understood what was happening. I was pretty sure my perspective would shift once I got better (which it did), so I didn’t let the nos carry me too far downstream.

It’s easy for one no to outweigh many yesses, so much so that we may not even notice the yesses when they occur. A Facebook friend used to post what she called “The Daily Yes.” It was a good prompt for me because it was my cue to pay attention to what’s juicy and zesty and working in my life—to who and what has said yes to me and who and what I’ve said yes to.

Don’t Let the Nos Foil Your Plans

The negativity bias can really wreak havoc on your attempts to meet your goals, master a challenge, or change an unwanted habit. Your brain is more likely to point out all the things you don’t do—or don’t do as well as you could or should—while ignoring your successes. Along with repetition and perseverance, change requires a cheerleader, not a critic scolding you from the peanut gallery.

If you allow the negativity bias to run unchecked, you’re likely to believe there are more nos than there actually are—and that they mean something. You’re likely to perceive anything that doesn’t work or turn out the way you planned as evidence that something is wrong with you or with your plan instead of using it as feedback to help you adjust your course.

Any time you’re trying to change the status quo is a good time to be intentional about counting your yesses. 

Note: Counting your yesses isn’t the same as positive thinking. Although positive thinking sounds like a good idea, it may be more of a hindrance to success than a help. Nor is positive thinking the same as optimism, which is a character trait. Positivity and optimism are desirable, but not to the point where your glasses become so rose-colored you’re unable to see through them.

Part of the series A-Z: An Alphabet of Change.

X Is for eXpectations

Life is an ongoing series of experiences, one after another after another. When you’re in the midst of one of them, you experience it. After it’s over, you explain it, meaning you remember it and tell a story about it, incorporating it into your ongoing narration.

But before anything even occurs, you have an expectation about what will or won’t happen, what should or shouldn’t happen, or how events will unfold and the consequences that are likely to ensue.

Expectation is

  • A belief about what should happen or the way things should be.
  • An estimate or forecast of a future situation based on present or past experiences.
  • Anticipation: looking forward to something, whether hopefully or fearfully.

Experience is:

  • The apprehension of an object, thought, or emotion through the senses or mind.
  • An event or a series of events participated in or lived through.
  • Direct personal participation or observation.

Explanation is:

  • A story about how or why something happened or turned out the way it did.
  • Rationalization, justification, and/or judgment about the experience.
  • The cognitive process of making something seem consistent with or based on reason.

There’s some degree of conscious (System 2) involvement in all three phases of an experience. But there’s even more unconscious (System 1) involvement in them.

The Way Things Should Be

According to Andy Clark, philosopher and cognitive scientist at the University of Edinburgh:

Our primary contact with the world…is via our expectations about what we are about to see or experience. 

Your expectations are constrained not only by what has already happened (your past experiences), but also—and even more significantly—by the stories (and explanations) you’ve constructed about them. Your expectations, arising from your mental model of the world, determine much of what you make of your experiences.

It’s worth remembering that your experience of what’s going on in your mind and in the world is not the same as what is actually going on in either your mind or in the world.

In addition to helping you navigate the terrain you inhabit, your mental model gives rise to your sense of the way things should be. It generates expectations that are either confirmed or denied, as well as assumptions, biases, etc., that determine what you pay attention to, what you perceive (even what you are able to perceive), how you interpret and respond to what you perceive, and the meaning you assign to it.

Who I am is the habit of what I always was and who I’ll be is the result. —Louise Erdrich

Although it doesn’t have to be, the cycle of expectation/experience/
explanation can be a vicious one that narrows your perspective—and your world.

Generating expectations isn’t something you are doing; it’s something your brain is doing. You may have come across advice to do away with expectations because they are either “self-defeating” or nothing but a prelude to disappointment. (Alexander Pope, Shakespeare, and Sylvia Plath are just a few who have linked expectations with disappointment.) The advice to eliminate them is based on a belief that expectations are consciously created, which gives us control over them.

Your Brain is Predictive, not Reactive.

Your felt experience may be that something happens and you react to it, but the reality is that your brain is not reactive but predictive. It is always doing its best to anticipate what’s going to happen next, as if it were playing a never-ending game of chess, continuously anticipating and preparing you for your next move.

Your brain generates multiple possible representations of what to expect in the environment. The representation with the smallest prediction error is selected. However the generation of representations is constrained by what is stored in memory and by the sampling of the environmentDirk De RidderJan Verplaetse, and Sven Vanneste, Frontiers in Psychology

You’re only aware of what your brain thinks you need to know, when you need to know it. Although your reactions and responses feel spontaneous and freely chosen, most of the time they are neither.

The unconscious is always several steps ahead of the conscious part of your brain. As neuroscientists have pointed out, this is what makes activities such as sports possible. If the brain was merely reactive, it wouldn’t operate fast enough to enable you to hit a baseball or block a goal. A reactive brain wouldn’t have helped Michael Phelps win his 10th gold medal while swimming blind after his goggles filled with water. All of his previous practice, experience, and knowledge gave his brain a solid basis for predicting what to expect and what he needed to do in order to win.

Because your brain is predictive:

  • You are not constantly surprised.
  • You don’t always have a choice.
  • You are able to engage in activities that require quick and accurate responses.
  • You are capable of learning from your experiences.
  • You don’t have to think about every little thing you do in the course of a day.
  • You find it difficult to change undesirable habits.
  • You may be tricked by various types of illusions.
  • You are unaware of your visual blind spot.

Your predictive brain—and the expectations it creates—can be a major obstacle when it comes to behavior change if you don’t take it into account. The neurons in your brain are constantly firing, interacting, and stimulating each other at various rates. If you stick to the belief that you always have a choice and try to use willpower to override your brain’s wiring, you will make things much harder for yourself than they need to be.

Not only can you not stop your brain from generating expectations, but doing so would be self-defeating. What you can do is become more aware of what those expectations are, check how closely they match reality, and evaluate how well they work for you in creating a satisfying and meaningful life.

Part of the series A-Z: An Alphabet of Change.