Let Go of the Learning Baggage

We all want to learn better. That means retaining information, processing it, being able to use it when needed. More knowledge means better instincts; better insights into opportunities for both you and your organization. You will ultimately produce better work if you give yourself the space to learn. Yet often organizations get in the way of learning.

How do we learn how to learn? Usually in school, combined with instructions from our parents, we cobble together an understanding that allows us to move forward through the school years until we matriculate into a job. Then because most initial learning comes from doing, less from books, we switch to an on-the-fly approach.

Which is usually an absolute failure. Why? In part, because we layer our social values on top and end up with a hot mess of guilt and fear that stymies the learning process.

Learning is necessary for our success and personal growth. But we can’t maximize the time we spend learning because our feelings about what we ‘should’ be doing get in the way.

We are trained by our modern world to organize our day into mutually exclusive chunks called ‘work’, ‘play’, and ‘sleep’. One is done at the office, the other two are not. We are not allowed to move fluidly between these chunks, or combine them in our 24 hour day. Lyndon Johnson got to nap at the office in the afternoon, likely because he was President and didn’t have to worry about what his boss was going to think. Most of us don’t have this option. And now in the open office debacle we can’t even have a quiet 10 minutes of rest in our cubicles.

We have become trained to equate working with doing. Thus the ‘doing’ has value. We deserve to get paid for this. And, it seems, only this.

What does this have to do with learning?

It’s this same attitude that we apply to the learning process when we are older, with similarly unsatisfying results.

If we are learning for work, then in our brains learning = work. So we have to do it during the day. At the office. And if we are not learning, then we are not working. We think that walking is not learning. It’s ‘taking a break’. We instinctively believe that reading is learning. Having discussions about what you’ve read, however, is often not considered work, again it’s ‘taking a break’.

To many, working means sitting at your desk for eight hours a day. Being physically present, mental engagement is optional. It means pushing out emails and rushing to meetings and generally getting nothing done. We’ve looked at the focus aspect of this before. But what about the learning aspect?

Can we change how we approach learning, letting go of the guilt associated with not being visibly active, and embrace what seems counter-intuitive?

Thinking and talking are useful elements of learning. And what we learn in our ‘play’ time can be valuable to our ‘work’ time, and there’s nothing wrong with moving between the two (or combining them) during our day.

When mastering a subject, our brains actually use different types of processing. Barbara Oakley explains in A Mind for Numbers: How to Excel at Math and Science (even if you flunked algebra) that our brain has two general modes of thinking – ‘focused’ and ‘diffuse’ – and both of these are valuable and required in the learning process.

The focused mode is what we traditionally associate with learning. Read, dive deep, absorb. Eliminate distractions and get into the material. Oakley says “the focused mode involves a direct approach to solving problems using rational, sequential, analytical approaches. … Turn your attention to something and bam – the focused mode is on, like the tight, penetrating beam of a flashlight.”

But the focused mode is not the only one required for learning because we need time to process what we pick up, to get this new information integrated into our existing knowledge. We need time to make new connections. This is where the diffuse mode comes in.

Diffuse-mode thinking is what happens when you relax your attention and just let your mind wander. This relaxation can allow different areas of the brain to hook up and return valuable insights. … Diffuse-mode insights often flow from preliminary thinking that’s been done in the focused mode.

Relying solely on the focused mode to learn is a path to burnout. We need the diffuse mode to cement our ideas, put knowledge into memory and free up space for the next round of focused thinking. We need the diffuse mode to build wisdom. So why does diffuse mode thinking at work generally involve feelings of guilt?

Oakley’s recommendations for ‘diffuse-mode activators’ are: go to the gym, walk, play a sport, go for a drive, draw, take a bath, listen to music (especially without words), mediate, sleep. Um, aren’t these all things to do in my ‘play’ time? And sleep? It’s a whole time chunk on its own.

Most organizations do not promote a culture that allow these activities to be integrated into the work day. Go to the gym on your lunch. Sleep at home. Mediate on a break. Essentially do these things while we are not paying you.

We ingest this way of thinking, associating the value of getting paid with the value of executing our task list. If something doesn’t directly contribute, it’s not valuable. If it’s not valuable I need to do it in my non-work time or not at all. This is learned behavior from our organizational culture, and it essentially communicates that our leaders would rather see us do less than trust in the potential payoff of pursuits that aren’t as visible or ones that don’t pay off as quickly. The ability to see something is often a large component of trust. So if we are doing any of these ‘play’ activities at work, which are invisible in terms of their contribution to the learning process, we feel guilty because we don’t believe we are doing what we get paid to do.

If you aren’t the CEO or the VP of HR, you can’t magic a policy that says ‘all employees shall do something meaningful away from their desks each day and won’t be judged for it’, so what can you do to learn better at work? Find a way to let go of the guilt baggage when you invest in proven, effective learning techniques that are out of sync with your corporate culture.

How do you let go of the guilt? How do you not feel it every time you stand up to go for a walk, close your email and put on some headphones, or have a coffee with a colleague to discuss an idea you have? Because sometimes knowing you are doing the right thing doesn’t translate into feeling it, and that’s where guilt comes in.

Guilt is insidious. Not only do we usually feel guilt, but then we feel guilty about feeling guilty. Like, I go to visit my grandmother in her old age home mostly because I feel guilty about not going, and then I feel guilty because I’m primarily motivated by guilt! Like if I were a better person I would be doing it out of love, but I’m not, so that makes me terrible.

Breaking this cycle is hard. Like anything new, it’s going to feel unnatural for a while but it can be done.

How? Be kind to yourself.

This may sound a bit touchy-feely, but it is really a just a cognitive-behavioral approach with a bit of mindfulness thrown in. Dennis Tirch has done a lot of research into the positive benefits of compassion for yourself on worry, panic and fear. And what is guilt but worry that you aren’t doing the right thing, fear that you’re not a good person, and panic about what to do about it?

In his book, The Compassionate-Mind Guide to Overcoming Anxiety, Tirch writes:

the compassion focused model is based on research showing that some of the ways in which we instinctively regulate our response to threats have evolved from the attachment system that operates between infant and mother and from other basic relationships between mutually supportive people. We have specific systems in our brains that are sensitive to the kindness of others, and the experience of this kindness has a major impact on the way we process these threats and the way we process anxiety in particular.

The Dalai Lama defines compassion as “a sensitivity to the suffering of others, with a commitment to do something about it,” and Tirch also explains that we are greatly impacted by our compassion to ourselves.

In order to manage and overcome emotions like guilt that can prevent us from learning and achieving, we need to treat ourselves the same way we would the person we love most in the world. “We can direct our attention to inner images that evoke feelings of kindness, understanding, and support,” writes Tirch.

So the next time you look up from that proposal on the new infrastructure schematics and see that the sun is shining, go for a walk, notice where you are, and give your mind a chance to go into diffuse-mode and process what you’ve been focusing on all morning. And give yourself a hug for doing it.

Mental Model: Hanlon’s Razor

If you ever feel that the world is against you, you are not alone.

We all have a tendency to assume that when anything goes wrong, the fault lies within some great conspiracy against us. A co-worker fails to give you a report in time? They must be trying to derail your career and beat you to a promotion. Your child drops and breaks an expensive plate? They must be trying to annoy you and waste your time. WiFi in a coffee shop not working? The staff must be lying about having it to lure you in and sample their crappy espresso.

But the simple fact is that these explanations which we tend to jump to are rarely true. Maybe your co-worker thought today was Tuesday, not Wednesday. Maybe your child had sticky hands from playing with play-doh. Maybe the WiFi router was just broken. This is where Hanlon’s razor comes in.

The Basics

Hanlon’s Razor is a useful mental model which can be best summarized as such:

‘Never attribute to malice that which can be adequately explained by neglect.’

Like Occam’s razor, this heuristic is a useful tool for rapid decision-making and intelligent cognition.

Applying Hanlon’s razor in our day-to-day lives, allows us to better develop relationships, become less judgmental, and improves rationality. Hanlon’s razor allows us to give people the benefit of the doubt and have more empathy. In this way, the value of Hanlon’s razor is pronounced in relationships and business matters.

It’s a simple fact that most of us spend a large part of our day communicating with others and making choices based on that. We all lead complex lives wherein (as Murphy’s law states) things are constantly going wrong. When this occurs, a common response is to blame the nearest person and assume they have malicious intent. People are quick to accuse corporations, politicians, their bosses, employees, coffee shop workers and even family of trying to derail them. When someone messes up around us, we forget how many times we too have done the same. We forget how many times we have elbowed someone in the street, knocked over a drink at a relative’s house or forgotten to meet a friend at the right time. Instead, the perpetrator becomes a source of intense irritation.

To assume intent in such a situation is likely to worsen the problem. None of us can ever know what someone else wanted to happen. The smartest people make a lot of mistakes. Inability or neglect is far more likely to be the cause than malice. When a situation causes us to become angry or frustrated, it can be valuable to consider if those emotions are justified. Often, the best way to react to other people causing us problems is by seeking to educate them, not to disdain them. In this way, we can avoid repeats of the same situation.


The phrase ‘Hanlon’s razor’ was coined by Robert J. Hanlon, but it has been voiced by many people throughout history, as far back as 1774.

Napoleon Bonaparte famously declared:

‘Never ascribe to malice that which is adequately explained by incompetence.’

Goethe wrote similarly in The Sorrows of Young Werther in 1774:

Misunderstandings and neglect create more confusion in this world than trickery and malice. At any rate, the last two are certainly much less frequent.

The German general Kurt von Hammerstein-Equord used Hanlon’s razor to assess his men, saying:

I divide my officers into four groups. There are clever, diligent, stupid, and lazy officers. Usually two characteristics are combined. Some are clever and diligent – their place is the General Staff. The next lot are stupid and lazy – they make up 90 percent of every army and are suited to routine duties. Anyone who is both clever and lazy is qualified for the highest leadership duties, because he possesses the intellectual clarity and the composure necessary for difficult decisions. One must beware of anyone who is stupid and diligent – he must not be entrusted with any responsibility because he will always cause only mischief.

The Place of Hanlon’s Razor in a Latticework of Knowledge

Hanlon’s razor works best when combined and contrasted with other mental models in our latticework of knowledge. Here are some examples of the useful interactions:

  • The availability heuristic. This mental model states we misjudge the frequency of recent events. In particular, this occurs if they are vivid and memorable. Many people have a tendency to keep an internal scorecard of other people’s mistakes. For example, imagine that a taxi driver takes a wrong turn and makes a journey more expensive. A month later, the same thing occurs with a different driver. We are likely to recall the previous event and react by seeing all taxi drivers as malicious. Instead of accepting both as simple mistakes, the availability of the memory makes us imagine malicious intent. By combining these two mental models, we can understand why certain situations provoke such strong emotions. When a memory is vivid and easy to recall, we may ignore Hanlon’s razor.
  • Confirmation bias. We all have a tendency to look for information which confirms preexisting beliefs. When cognitive dissonance arises, we aim to realign our worldviews. Overcoming confirmation bias is a huge step towards making better choices motivated by logic, not emotions. Hanlon’s razor assists with this. If we expect malicious intent, we are likely to attribute it wherever possible. For example, if someone sees a certain politician as corrupt, they will look for information which confirms that. They become unable to identify when mistakes are the result of incompetence or accident.
  • Bias from disliking/hating. Hanlon’s razor can provide insights when we deal with people, institutions, or entities which we dislike. The more we dislike someone or something, the more likely we are to attribute their actions to malice. When someone we dislike makes a mistake, reacting with empathy and understanding tends to be the last response. Acting in an emotional way is natural, yet immature. It can only worsen the situation. The smartest solution is, no matter how much we dislike someone, to assume neglect or incompetence.
  • We also like to attribute our own flaws and failures to someone else, which is a cheap psychological protective mechanism called projection. This allows us to maintain a positive self-image and view friction as someone else’s fault rather than our own. It’s best to run a reality check before blaming others.

The Uses of Hanlon’s Razor

The Media

Modern media treats outrage as a profitable commodity. This often takes the form of articles which attribute malice to that which could be explained by incompetence or ignorance. We see examples of this play out in the media multiple times a day. People rush to take offense at anything which contradicts their worldview or which they imagine to do so. Media outlets are becoming increasingly skilled at generating assumptions of malicious intent. When looking at newspapers, websites, and social media, it can be beneficial to apply Hanlon’s razor to what we see.

For example, when Apple’s Siri voice search launched, people noticed that it could not search for abortion clinics. This was immediately taken up as proof of misogyny within the company when in fact, a programming error caused the problem.

A similar issue has occurred a number of times with YouTube content policies. When videos discussing LGBTQ matters were filtered on the restrictive viewing mode, many people took extreme offense at this. The reality is that again, this was an algorithm error and not a case of homophobia on the part of their programmers. Countless videos which do not discuss anything related to LGBTQ issues have also been filtered. This shows it to be a case of confirmation bias, wherein people see the malice they expect to see.

Communication and Relationships

One of the most valuable uses of Hanlon’s razor is in relationships and communication. It is common for people to damage relationships by believing other people are intentionally trying to cause problems for them, or behaving in a way intended to be annoying. In most cases, these situations are the result of inability or accidental mistakes.

Douglas Hubbard expanded upon the idea in Failure of Risk Management: Why it’s Broken and How to Fix it:

I would add a clumsier but more accurate corollary to this: ‘Never attribute to malice or stupidity that which can be explained by moderately rational individuals following incentives in a complex system of interactions.' People behaving with no central coordination and acting in their own best interest can still create results that appear to some to be clear proof of conspiracy or a plague of ignorance.

A further example can be seen when semantic barriers interfere with communication. We have all encountered people struggling to speak our native language, perhaps because they are a tourist or have recently moved to the county. You have probably seen someone gets frustrated at them or even been the one getting annoyed. Or if you have ever traveled to or lived in a country where you are not fluent in the language, you might have been the one people got annoyed at. Realistically, the person asking you for directions or struggling to order their coffee is not mixing up their nouns and speaking in a strong accent on purpose.

Hanlon’s razor tells us they are merely inarticulate and are not trying to waste anyone’s time. The same issues occur when a person uses language which is considered too complex or too basic. This may form a semantic barrier, as other people assume they are trying to confuse them or are being blunt.

A short-cut to regulating what can be strong reactions to inadvertent events is to conscientiously reframe the perpetrator as a toddler knocking over a vase. Their actions are rendered unintentional and clumsy, highlighting their need for help, maturation or supervision, allowing you to rapidly regain composure and not take it personally.

Exceptions and Issues

Like any mental model, Hanlon’s razor has its limitations and its validity has been contested. Some critics consider Hanlon’s razor to be an overly naive idea which can blind people to true malice. While people have malicious intent far less often than we think, it is still something which must be taken into account. Sometimes actions which could be attributed to incompetence are in fact consciously or unconsciously malicious.

An instance of Hanlon’s razor being proven wrong is the mafia. Prior to the 1960s, the existence of the mafia was considered to be a conspiracy theory. Only when a member contacted law enforcement, did police realize that the malice being perpetrated was carefully orchestrated.

To make the best use of Hanlon’s razor, we must be sure to put it in context, taking into account logic, experience, and empirical evidence. Make it a part of your latticework of mental models, but do not be blind to behavior which is intended to be harmful.

Language: Why We Hear More Than Words

It’s a classic complaint in relationships, especially romantic ones: “She said she was okay with me forgetting her birthday! Then why is she throwing dishes in the kitchen? Are the two things related? I wish I had a translator for my spouse. What is going on?”

The answer: Extreme was right, communication is more than words. It’s how those words are said, the tone, the order, even the choice of a particular word. It’s multidimensional.

In their book, Meaning and Relevance, Deirdre Wilson and Dan Sperber explore the aspects of communication that are beyond the definitions of the words that we speak but are still encoded in the words themselves.

Consider the following example:

Peter got angry and Mary left.

Mary left and Peter got angry.

We can instantly see that these two sentences, despite having exactly the same words, do not mean the same thing. The first one has us thinking, wow, Peter must get angry often if Mary leaves to avoid his behavior. Maybe she’s been the recipient of one too many tantrums and knows that there’s nothing she can do to diffuse his mood. The second sentence suggests that Peter wants more from Mary. He might have a crush on her! Same words – totally different context.

Human language is not a code. True codes have a one-to-one relationship with meaning. One sound, one definition. This is what we see with animals.

Wilson and Sperber explain that “coded communication works best when emitter and receiver share exactly the same code. Any difference between the emitter’s and receiver’s codes is a possible source of error in the communication process.” For animals, any evolutionary mutations that affected the innate code would be counter-adaptive. A song-bird one note off key is going to have trouble finding a mate.

Not so for humans. We communicate more than the definitions of our words would suggest. (Steven Pinker argues language itself as a DNA-level instinct.) And we decode more than the words spoken to us. This is inferential communication, and it means that we understand not only the words spoken, but the context in which they are spoken. Contrary to the languages of other animals, which are decidedly less ambiguous, human language requires a lot of subjective interpretation.

This is probably why we can land in a country where we don’t speak the language and can’t read the alphabet, yet get the gist of what the hotel receptionist is telling us. We can find our room, and know where the breakfast is served in the morning. We may not understand her words, but we can comprehend her tone and make inferences based on the context.

Wilson and Sperber argue that mutations in our inferential abilities do not negatively impact communication and potentially even enhance it. Essentially, because our human language is not simply a one-to-one code because more can be communicated beyond the exact representations of certain words, we can easily adapt to changes in communication and interpretation that may evolve in our communities.

For one thing, we can laugh at more than physical humor. Words can send us into stitches. Depending on how they are conveyed, the tone, the timing, the expressions that come along with them, we can find otherwise totally innocuous words hysterical.

Remember Abbott and Costello?

Who’s on first.”
“No, what’s on second.”

Consider Irony

Irony is a great example of how powerfully we can communicate context with a few simple words.

I choose my words as indicators of a more complex thought that may include emotions, opinions, biases, and these words will help you infer this entire package. And one of my goals as the communicator is to make it as easy as possible for you to get the meaning I’m intending to convey.

Irony is more than just stating the opposite. There must be an expectation of that opposite in at least some of the population. And choosing irony is more of a commentary on that group. Wilson and Sperber argue that “what irony essentially communicates is neither the proposition literally expressed not the opposite of that proposition, but an attitude to this proposition and to those who might hold or have held it.”

For example

When Mary says, after a boring party, ‘That was fun’, she is neither asserting literally that the party was fun nor asserting ‘ironically’ that the party was boring. Rather, she is expressing an attitude of scorn towards (say) the general expectation among the guests that the party would be fun.

This is a pretty complex linguistic structure. It allows us to communicate our feelings on cultural norms fairly succinctly. Mary says ‘That was fun’. Three little words. And I understand that she hated the party, couldn’t wait to get out of there, feels distant from the other party-goers and is rejecting that whole social scene. Very powerful!

Irony works because it is efficient. To communicate the same information without irony involves more sentences. And my desire as a communicator is always to express myself in the most efficient way possible to my listener.

Wilson and Sperber conclude that human language developed and became so powerful because of two unique cognitive abilities of humans, language and the power to attribute mental states to others. We look for context for the words we hear. And we are very proficient at absorbing this context to infer meaning.

The lesson? If you want to understand reality, don't be pedantic.

Philosopher Kahlil Gibran on The Tension Between Reason and the Silence Required for Thinking

Kahlil Gibran (1883–1931) published his masterpiece, The Prophet, in 1923. The work endures as a timeless meditation on the art of living. Gibran's thoughts on love and giving offer a glimpse into his genius.

Reminding one of the struggle most of us have with the three marriages, Gibran illuminates the beautiful struggle that exists within all of us between reason and passion.

Your soul is oftentimes a battlefield, upon which your reason and your judgment wage war against your passion and your appetite.
Would that I could be the peacemaker in your soul, that I might turn the discord and rivalry of your elements into oneness and melody.
But how shall I, unless you yourselves be also the peacemakers, nay, the lovers of all your elements.

Your reason and your passion are the rudder and the sails of your seafaring soul.
If either your sails or your rudder be broken, you can but toss and drift, or else be held at a standstill in mid-seas.
For reason, ruling alone, is a force confirming; and passion, unattended, is a flame that burns to its own destruction.
Therefore let your soul exalt your reason to the height of passion, that it my sing.
And let it direct your passion with reason, that your passion may live through its own daily resurrection, and like the phoenix rise above its own ashes.

As for his final piece of advice, on the tension between reason and passion, Gibran suggests something we should all take to heart, “rest in reason and move in passion.”

Just as there is a required solitude in leadership, there is a silence required for thinking. Increasingly, however, we use devices from iPhones and Echo's to entertain and reduce our ability to be present with ourselves. When it comes to Speaking and Talking, Gibran offers:

You talk when you cease to be at peace with your thoughts;
And when you can no longer dwell in the solitude of your heart you live in your lips, and sound is a diversion and a pastime.
And in much of your talking, your thinking is half murdered.
For thought is a bird of space, that in a case of words may indeed unfold its wings but cannot fly.

There are those among you who seek the talkative through fear of being alone.
The silence of aloneness reveals to their eyes their naked selves and they would escape.
And there are those who talk, and without knowledge or forethought reveal a truth which they themselves do not understand.
And there are those who have the truth within them, but they tell it not in words.

The Prophet goes on to explore love, marriage, children, crime and punishment and so much more. Complement with German Philosopher Arthur Schopenhauer on the Dangers of Clickbait.

General James Mattis: Arm Yourself With Books

How many situations will you face that have not already been experienced by someone else? Billions of people, thousands of years … probably not too many. It’s been done.

Luckily, sometimes those experiences are captured by history, and thus they become valuable tools for us to learn and prepare for similar situations. This is part of the central ethos of Farnam Street.

In an email that went viral in 2013, U.S. Marine General James Mattis (now the U.S. Secretary of Defense) candidly wrote about the value of this approach near the beginning of the Iraq War. Advising a colleague, he wrote:

Thanks to my reading, I have never been caught flat-footed by any situation, never at a loss for how any problem has been addressed (successfully or unsuccessfully) before. It doesn’t give me all the answers, but it lights what is often a dark path ahead.

Speaking specifically about situations he faced in the context of his military role, he said “We have been fighting on this planet for 5,000 years and we should take advantage of their experience. ‘Winging it’ and filling body bags as we sort out what works reminds us of the moral dictates and the cost of incompetence in our profession.”

Whatever country you are fighting a war in, someone has already fought there before. Someone has also explored it, mapped it, studied it, and done humanitarian work there. The hard work has already been done. All you have to do is read.

Maybe Napoleon shouldn’t have dismissed the Swedish accounts on the perils of invading Russia. He might have learned that the Russians didn’t follow the traditional norms of warfare. They weren’t going to surrender, or even admit to losing a battle, not with thousands of miles of country to withdraw into, scorching the earth along the way. And also that the Russian winter is really, really, harsh. 130 years later, with Napoleon’s experience to draw from, it’s staggering that Hitler went down the same path. He got the same results.

Books have a limitless amount to teach us if we're willing to pay attention.

You don’t need to be a military general to benefit from the fore-arming and forewarning that books can provide. Ask yourself, what body of knowledge would I benefit from having deep in my bones? Unless you're trying to make discoveries in fundamental physics or advanced technology, someone else has probably already gained the knowledge that you seek, and they likely have put it in a book to share with you.

Learning how to read for wisdom is simple, but not easy. The payoffs though, can be incredible.

The more you read, the more you will build your repertoire. Incrementally at first, the knowledge you add to your stockpile will grow over time as it combines with everything new you put in there. This is called compounding, and it works with knowledge much the same as it does with interest. Eventually, when faced with the new, challenging, and perplexing, you will be able to draw on this dynamic inner repository.

You will react, not as a neophyte, but as someone whose instincts have been honed by the experiences of others, rather than just your own. You will start to see that nothing is truly new, that awesome challenges can and have been overcome, and there are fundamental truths to how the world works.

So learn from others. Figure out where you are going and find out who has been there before. Knowledge comes from experience, but it doesn’t have to be your experience. Deep reading helps you to understand the world allowing you to conquer panic and maximize your chances of success.

If you're interested in military matters, you might even start with Mattis' reading list itself.

Warnings From Sleep: Nightmares and Protecting The Self

“All of this is evidence that the mind, although asleep, is constantly concerned about the safety and integrity of the self.”


Rosalind Cartwright — also known as the Queen of Dreams — is a leading sleep researcher. In The Twenty-four Hour Mind: The Role of Sleep and Dreaming in Our Emotional Lives, she explores the role of nightmares and how we use sleep to protect ourselves.

When our time awake is frightening or remains unpressed, the sleeping brain “may process horrible images with enough raw fear attached to awaken a sleeper with a horrendous nightmare.” The more trauma we have in our lives the more likely we are to experience anxiety and nightmares after a horrific event.

The common feature is a threat of harm, accompanied by a lack of ability to control the circumstances of the threat, and the lack of or inability to develop protective behaviors.

The strategies we use for coping effectively with extreme stress and fear are controversial. Should we deny the threatening event and avoid thinking about it better than thinking about it and becoming sensitized to it?

One clear principle that comes out of this work is that the effects of trauma on sleep and dreaming depend on the nature of the threat. If direct action against the threat is irrelevant or impossible (as it would be if the trauma was well in the past), then denial may be helpful in reducing stress so that the person can get on with living as best they can. However, if the threat will be encountered over and over (such as with spousal abuse), and direct action would be helpful in addressing the threat, then denial by avoiding thinking about the danger (which helps in the short-term) will undermine problem-solving efforts and mastery in the long run. In other words, if nothing can be done, emotion-coping efforts to regulate the distress (dreaming) is a good strategy; but if constructive actions can be taken, waking problem-solving action is more adaptive.

What about nightmares?

Nightmares are defined as frightening dreams that wake the sleeper into full consciousness and with a clear memory of the dream imagery. These are not to be confused with sleep terrors. There are three main differences between these two. First, nightmare arousals are more often from late in the night’s sleep, when dreams are longest and the content is most bizarre and affect-laden (emotional); sleep terrors occur early in sleep. Second, nightmares are REM sleep-related, while sleep terrors come out of non-REM (NREM) slow-wave sleep (SWS). Third, sleepers experience vivid recall of nightmares, whereas with sleep terrors the experience is of full or partial amnesia for the episode itself, and only rarely is a single image recalled.

Nightmares abort the REM sleep, a critical component of our always on brain, Cartwright explains:

If we are right that the mind is continuously active throughout sleep—reviewing emotion-evoking new experiences from the day, scanning memory networks for similar experiences (which will defuse immediate emotional impact), revising by updating our organized sense of ourselves, and rehearsing new coping behaviors—nightmares are an exception and fail to perform these functions.

The impact is to temporarily relieve the negative emotion. The example Cartwright gives is “I am not about to be eaten by a monster. I am safe in my own bed.” But because the nightmare has woken me up, the nightmare is of no help in regulating my emotions (a critical role of sleep). As we learn to manage negative emotions while we are awake, that is, as we grow up, nightmares reduce in frequency and we develop skills for resolving fears.

It's not always fear that wakes us from a nightmare. We can also be woken by anger, disgust, and grief.

Cartwright concludes, with an interesting insight, on the role of sleep in consolidating and protecting “the self.”:

[N]ightmares appear to be more common in those who have intense reactions to stress. The criteria cited for nightmare disorder in the diagnostic manual for psychiatric disorders, the Diagnostic and Statistical Manual IV-TR (DSM IV-TR), include this phrase “frightening dreams usually involving threats to survival, security, or self-esteem.” This theme may sound familiar: Remember that threats to self-esteem seem to precede NREM parasomnia awakenings. All of this is evidence that the mind, although asleep, is constantly concerned about the safety and integrity of the self.

The Twenty-four Hour Mind goes on to explore the history of sleep research through case studies and synthesis.