The Secret Music That’s Always Playing in Your Head

Listening to music is one of the most compelling human experiences. Music taps deeply into our sense of feeling, often highlighting and perhaps even giving a voice to our emotions.

For this reason, it’s no surprise that in Holhe Fels cave in the hills of west Ulm Germany, archeologists discovered an ancient flute that carbon dates to 35,000 years ago. What’s kind of surprising is that it’s made of a vulture bone.

What’s very surprising is that it’s tuned to the pentatonic scale.

The pentatonic scale is the set of notes virtually every song you know is built on. Everything from German Baroque to ragtime to West African music to to jazz to Sami joik singing to polka to third-wave Canadian psychobilly, and even that earworm that was in your head all of yesterday, the one you finally managed to shake a few minutes ago.

Fundamentally, music is just a set of vibrations operating at a frequency level (measured in Hz or cycles per second) detectable to human ears, which our brains translate into something enjoyable.

Of course, there are all kinds of frequencies we can’t detect. Dog whistles, of course, play too high for our ears to register, and some theorize that the reason animals sometimes flee an area prior to earthquake or tsunami is that they’re picking up on extremely low frequencies created by the oncoming waves or tremors.

Aside from perhaps that earworm stuck in your head again, there is a totally different kind of music going on in your brain at this very moment, one that you’ll never hear. In fact, there are a number of frequency patterns, or waves, that your brain generates based on specific neural activity.

In an article for Thought Medicine, Linda Gabriel explains, “There are 4 basic wave frequencies and each correlates with a specific state of consciousness. Like sound frequencies, brain waves are measured in Hz. In general, the slower the frequency of your brain waves, the more relaxed you feel.”

Beta Waves operate between 13-30Hz. These resonate when you are concentrating, trying to pay attention, or diligently reading posts on blogs. When you are worrying about whatever you worry about, that’s some Beta music at work.

Switch on your TV or your computer screen for a little relaxing mindless surfing, you’ve just changed your brain’s radio station to Alpha Waves, which operate at 8-13Hz. This state is sometimes referred to as a “hypnogogic” state associated with the very beginning of a meditative experience. Alpha Waves are considered by some to be the connector between the conscious and subconscious mind.

Theta Waves
operate between 4-8Hz. They occur when you’re in the deepest state of REM (rapid eye movement) sleep. Testing shows younger children appear to be operating in Theta for the majority of their day. If you are skilled at meditation, you are very familiar with blissed out sense associated with Theta Waves. So Swamis and kids have it figured out. When you found yourself daydreaming, or dropping into the ‘Ghost Curve’ during your boss’s last presentation, you’ve got a little touch of Theta action going on.

Delta Waves
operate at 4 HZ.  This is often referred to as ‘slow wave’ sleep and you’ll find yourself experiencing this after a bout with insomnia. This is the brain in recovery mode. If you drink too much, you’ll interfere with your Delta sleep waves. Conversely, a low carb diet will increase Delta activity. This is when you’re totally zonked out; no dreaming occurs in this state. This is how we might imagine bears during hibernation.

Neuroscientists are experimenting with different forms of meditation to actively induce different brain wave states. In other words, you can, with practice, consciously control your brain waves. It’s not all that different than the idea of changing to another radio station, or flipping to the next song on your playlist.

Even though you can’t hear your brain waves, like music, they are deeply associated with how you feel. The orchestration of neural activity is much like a beautifully balanced symphony where the harmonic resonance is perfectly aligned between all of the musicians.

Just think, it’s nonstop concerts going on in your head every day of your life, and it’s all free.  Too bad you can’t actually hear it.

Straws, Steps, and the Importance of Thinking Small

There is a famous Arabic proverb where a camel loaded beyond capacity collapses after a single straw too many, hence, ‘the straw that broke the camel’s back.’ The idea is a basic one: a small, seemingly inconsequential, event ends up having profound effects.

Exactly one hundred Fridays ago, I began posting on this blog. In my writing and research, I have been struck by one reoccurring theme: the simplicity and elegance of the single increment, the power of potentiality unleashed through a minute action.

“A journey of a 1000 miles must begin with the first step.” This quote is sometimes attributed to the Chinese philosopher Lao Tzu, but the concept also resonates in Daniel Coyle’s talent code, Anders Ericson’s 10,000 hours rule, and JB Foot’s tiny habit.

It’s the compounding effect of building on a single decision, and that crucial first step overcomes inertia for creating a new habit.

The process is understood: practice builds repetition, which in turn builds habit. Habit is really nothing more than mylenated neural code put into action. But, of course, knowing is not the same as doing.

Our lives are a complex dance of experience, interpreted through the lens of emotion, and it’s difficult in the moment to comprehend the swirl around us. Even when our goals and aspirations are clearly defined, actually getting there proves difficult.

It’s not the knowing; for the most part, we know what we should do or want to do. In some way, it is the very simplicity of that initial step that lures us away from it, as though somehow there has to be more to it than that.

And yet, maybe there isn’t. Water boils at 212 degrees Fahrenheit. At 211 degrees, all you have is really hot water. Raise the temperature one degree and steam is generated, and steam has the power to run a city’s electrical grid.

Someone had to lay that first stone at the pyramid of Giza, Itzak Perlman had to run his bow across a violin string for the first time, Michael Jordan had to shoot his first layup, and Mark Twain had to write the first word in Huckleberry Finn.

As the process plays out, tiny steps build into something much greater than merely the sum of incremental parts. Nothing illustrates this better than a bird’s nest. Bits of debris, twigs and straw, when woven together, create an amazingly resilient and viable structure that has served our feathered friends for millions of years.

The straw that broke the camel’s back is a parable of warning (I suspect that’s how the camel understands it), but it can also be reframed as the awesome power contained in a single straw.

The last hundred weeks have been an interesting and rewarding journey. Thank you for taking a step down that road with me.

My sincere appreciation to my editor extraordinaire, Jessica. (Editor’s note: aw, thanks!)

See you next week.

Robb Best

Seeing Red, or, The Superpower You May Not Even Know You Have

I don’t need to tell you that sight is important for most people. It is estimated that the brain devotes 50% of its activity to processing our visual sensory experience.

As a child, it’s likely you contemplated an idea that went something like this: “I wonder if the color red I’m seeing is the exact same color red my friend sees?” That question, framed in scientific terms, asks, “Is there strict commonality in the way any two brains process the same visual representation?”

Interestingly, it’s only very recently that neuroscientists have begun to shed some light on this issue. In fact, light plays a key part in the story. But before we get to the answer, it’s important to understand that some people, and by that I mean some women, have been shown to have visual super powers.

The retinas in our eyes process light through conical structures made up of neurons. Most of us have three types of cones. Sounds pretty basic, yet various permutations of those three cone types let us perceive about a million different color shades.  If you have all three types of cones, you’re considered to be a trichromat. If you’re born with only two kinds of cones, you’re dichromatic—also known as colorblind.

However, it appears that a relatively small percentage of women have a fourth color cone. If you won the four-cone lottery, you’re called a tetrachromat. Unfortunately, most of those tetrachomats don’t use their fourth cone, so they wind up seeing the same colors as the rest of us.

After a twenty year quest, armed with very sophisticated equipment for visual color diagnostics, neuroscientist Gabriela Jordan and her team had a breakthrough in 2010. They discovered a woman living in England who was a functional tetrachomatic.

Jordan explained it to Discover Magazine like this, “We now know tetrachromacy exists. But we don’t know what allows someone to become functionally tetrachromatic, when most four-coned women aren’t.’”

How much difference can one extra cone make? Tetrachromats can see a hundred million more color shades than the rest of us.

And yet if you’re a functioning tetrachromat, it’s likely you’re unaware of it because you have no way of understanding on how much deeper your color shading is by comparison.

So if by chance you are both a woman and a functional tetrachromat, you were born with a real super power. You may not exactly be Superman or Superwoman, but compared to other humans, you’ve got a secret ability all the same.

One that presents a world so extraordinary that it boggles most minds. One that, from your vantage point, is simply, you know, Tuesday.

In the end, we both may see the exact same red; it’s just that if you’re a tetrachromat, you see a hundred million more shades of it than I do.

The Twain Brain, or, Why Smart People do Stupid Things

“A man who carries a cat by the tail learns something he can learn in no other way.” So said Mark Twain, printer, steamboat pilot, journalist, failed miner, entrepreneur, abolitionist, lecturer and supreme humorist. Twain is perhaps the greatest American storyteller and writer ever produced by the fifty states.

Whether attacking kings, hypocrites, or the literary offenses of Fenimore Cooper, Twain was famous for his razor-sharp wit and his allergy to BS. Yet that same man drove himself into bankruptcy, ignoring the council of his most trusted pals in favor of pouring his fortune into a series of disastrous inventions. He once invested the equivalent of 8 million dollars in the Paige typesetting machine, a marvel of engineering that dazzled crowds but also constantly broke and was obsolete by about 1884.

So why did a man renowned for not suffering fools pour his fortune into one fool’s errand after another? Could it be that Twain, like the rest of us, was seduced by a “magic bullet”? That wholly American notion that there is a shortcut out there to unmitigated wealth and happiness.

Whether it’s a diet pill (all-natural, of course) or a potion to restore skin texture to that of a six-week-old baby (all-natural, of course) or a book that promises to create a state of nirvana (no artificial additives) or a new-fangled typesetter machine, many of us are suckers for the shortcut.

We love the easy road, the secret sauce, or that ultimate financial tip (see Martha Stewart). In 2012, Americans spent a total of $78 billion on lottery tickets.

Our brains love shortcuts. The most primitive, basic parts of our brains are wired for them. Although these shortcuts lack precision and can create real problems, their saving grace is efficiency.

Still, this efficiency can suffer sometimes. Take optimism bias, the unfounded belief that things will turn out much better than the facts warrant.

It’s what allows smokers to believe they won’t get cancer, dieters to start their diet in the future, and all of us to procrastinate on our work because, as Twain noted, “Never put off till tomorrow what you can do the day after tomorrow.”

Even the great Twain fell victim to optimism bias as he traveled down what he thought was a shortcut to financial independence through a prototype-printing machine. The Paige typesetter was reported to possess more problems than actual moving parts, of which it had more than 18,000.

Ironically, many suspect that had Twain put more energy in writing and less in his pet get-rich-quick scheme, he would have gotten rich much faster, and with a whole lot less heartache.

But Twain, was plagued with one incurable problem: a human brain. If reasoning is currency, then biases and shortcuts are what the primitive brain trades in. And that brain is where the action is.

Perhaps rather than seeing biases and shortcuts as system flaws, we should instead celebrate that which makes our brains so unique and ‘predictably irrational.’

No one summed it up better than Mark Twain.

“Don’t part with your illusions. When they are gone, you may still exist, but you have ceased to live.”

The Anatomy of Fear

By the time our ancestors were roaming the great savannas, alternating between chasing prey and being prey, their systems had already adapted to face the harsh environment, according to Rick Hanson PhD, author of Buddha’s Brain: The Practical Neuroscience of Happiness, Love, and Wisdom.

Today, those ancient adaptations show up in the most peculiar ways as we constantly hijack a system built for times long ago. Getting cut off on the highway might not seem an awful lot like being chased by a lion, but to the brain’s subcortical structures, it’s pretty much the same deal.

Hanson explains how it all works.

As you feel yourself careening across a lane of traffic, your brain sounds the ancient ‘lion alarm,’ and begins to prepare for battle. First, stress hormones like Epinephrine kick your heart rate up and Norepinephrine increases blood flow to bring your largest muscles online faster.  Your pupils dilate to take in more light for enhanced visibility, and your bronchioles expand, boosting lung capacity for punching and speed.

Another stress hormone called cortisol jumps in to suppress your immune inflammation warning system, just in case you happened to be wounded. The hippocampal system, which normally does its part to keep the cortisol level of the amygdala (the brain’s fear center) under wraps, takes a proverbial step back and lets the amygdala ratchet up, which drives more cortisol into your system, in effect supercharging your blood, much like adding octane to your vehicle’s gas tank.

The system that governs reproduction essentially turns off, because that’s not something that you’re likely to be thinking about at the moment, and your digestive system also goes into hibernation, allowing the body to redirect energy and blood flow as needed.

All of this signals your amygdala to go on a higher level alert; this system, which normally monitors threatening information, turns up the heat on your emotional thermometer and moves the needle from stress to fear/anger in order to raise your level of intensity commensurate with a struggle for life or death.

Your prefrontal cortex, the home of reason, speculation, planning and assessment gets hijacked by more primitive systems like the amygdala and takes a backseat, fundamentally turning the keys to your body over to your reptilian brain. Not a whole lot of contemplation going down when you’re in “kill or be killed” mode.

There was a time when the primitive elegance of this system made sense. But that was a long time ago. Today a whole host of activities, from being cut off on the road to a bad email from your boss, can trip the ancient survival system.

Many people find it difficult to deactivate the stress switch. Hanson teaches that practicing mindfulness and meditation are ways to help keep the brain from prematurely sounding the alarm bell all day long.

Sadly, for all too many people, there is a lion lurking around every corner.

What Your Grandma and Corporations Have in Common

Imagine your grandma just celebrated her 85th birthday. She’s beginning to forget things, but her doctor has reassured you that since, if given enough time, she can eventually pull the information through, it’s probably not Alzheimer’s.

You take some comfort in a recent study that suggests memory retrieval problems might not necessarily be the deterioration of synaptic connections, but more of a space issue.

Think of Grandma’s hippocampus like a library that, over time, has run out of shelving for the books. As they begin to pile up on the floor, the librarian can still find that edition of Twain’s Huckleberry Finn you’re after, but it takes a a little more time to scour all the nooks and crannies of the library to locate it. The same might be true for the hippocampus, the memory library.

In any event, modern medicine has been good to Grandma. The old family general practitioner has been replaced by a whole bevy of doctors who specialize in any number of medical fields. She’s got her heart specialist, her eye, ear, nose and throat doctor, her podiatrist, her diabetes doctor, her osteopath, and so on.

As a result, she finds herself traveling a regular circuit of doctors, each dedicated to improving the quality of her life and each taking advantage of the latest discoveries in pharmaceutical science.

Pharmaceutical science, like all science, operates on the principal of reduction theory—in essence, that the key to solving problems is to break them down into their smallest components and observe cause and effect. Molecular biology, and thus virtually every modern drug, is the result of this process. This systematic approach has literally built the technological world of modern humans.

There is one key problem with this approach. When you begin to examine complex systems like the human body, the reductionist technique begins to falter. Humans are composed of a myriad of structures that interact with each other, and depend on each other. The tangle of where one system begins and another end is difficult to understand, let alone observe.

For this reason, it makes more sense to understand a human being not as a series of mini structures or systems, but as one giant complex system. We need to think holistically.

When the heart doctor prescribes a heart medication, unless he knows what all the other speciality doctors have prescribed Grandma, and further understands the dynamic effect that might be created through the intermingling of medications, he might be setting her up for catastrophe and a trip to the ER. All of this despite his best intentions.

This is the peril of not recognizing that in a complex system, cause and effect relationships with other parts of the system can be significantly delayed and mask the dangers of your actions. Furthermore, the fact that internal organs are connected means the medication Grandma’s taken doesn’t necessarily move through her system in an isolated or linear fashion. Her heart medication might affect her heart, other medications, and/or other organs in unpredictable ways.

The effects of a medication can travel through the body like a metastasizing cancer, moving out in all directions simultaneously. The net result shows up as a cascading series of outcomes, leaving the simple, reductionist-driven ER doc in its wake.

Like Grandma’s body, today’s corporations have their own dizzying structure of interdependencies. Departments like sales, marketing, manufacturing, logistics, human resources, IT, and a slew of other departments abound, with more bound to come on the heels of new technological developments.

In many corporations, the depth of departmental interconnectivity and dependency is not completely recognized or understood, just like Grandma’s specialists don’t always understand the compounding effect of their actions in relationship to the body as a whole.

The nonlinear aspects of complex systems and delayed cause and effect loops can doom a company in the same way Grandma’s new heart medication may negatively impact her other medications.The end result can put Grandma in the ER, and a corporation on its back.


Stay tuned for Part 2. Next week we’ll learn the tricks to keeping your Grandma—and your favorite corporation—alive.

Want a Brain Boost? Try a Jog—or a Curry

Exercise: you know you should, and yet for many, vanity might not be enough to get you on the old treadmill first thing in the morning.

So if that isn’t getting you out of bed and into your sneakers, perhaps your brain might do it. No, not do your exercise, but rather, provide the best argument for working up a sweat.

It turns out that during strenuous physical activity, your brain produces a neural chemical called brain-derived neurotropic factor, or BDNF for short.

In his book Spark, The Revolutionary New Science of Exercise, Harvard psychiatrist John J Ratey refers to BDNF as “Miracle-Gro for the brain.” Why the fertilizer reference? BDNF strengthens the brain’s electrical connections by boosting their strength and vitality. This means that BDNF plays a vital role in the brain’s ability to rewire itself, often referred to as plasticity.

In an interesting study done in Germany, two groups faced off on treadmills. The first group supplemented their 45-minute exercise routine with two separate 3-minute intervals of intense sprinting. The control group didn’t include the high intensity sprinting intervals.

In subsequent memory tests, the sprinting group showed a 20% increase in word acquisition over the non-sprinters. Not surprisingly, the sprinters showed increased levels of BDNF, where the non-sprinters showed no difference.

Neuroscientist John Medina recommends in his book Brain Rules that we exercise 5 days a week for 30 minutes a day at an aerobic level. Recent Scottish studies support the German findings: extra bursts of brief, high-intensity exercise have a profound effect.

Memory improvement not convincing enough for you? How about kicking your mood up a notch? The neurotropic factor released during exercise appears to increase the output of dopamine and serotonin. Both are associated with well-being and enhanced mood.

Not into exercise? What about Indian food?

Another way to boost your BDNF is by consuming curcumin. It’s one of the main components of the spice tumeric, and according to Dr. Andrew Weil, it’s also “a powerful antioxidant with anti-inflammatory properties.” You can find tumeric in most commercial curry powders, or on its own as a flavoring and a natural food dye.

So tomorrow morning, do your brain a favor and jump on the treadmill. Afterwards, sprinkle a healthy helping of turmeric on your Cheerios. Or better yet, treat yourself to a nice yellow curry at your favorite Indian haunt tomorrow evening. Or do both—your call.

The Experiencing Self, or, Why Present-You Hates Past-You

Unlike Calvin here, most of us will probably never get the opportunity to have a face-to-face conversation between our current selves and our 6:30 selves, so to speak. That is a shame, because as Daniel Kahneman discusses in Thinking, Fast and Slow, the two of them don’t necessarily know that much about each other.

In trying to understand how the brain registers emotion, Kahneman outlines the divide between what he calls the “experiencing self” and the “remembering self.” The experiencing self, or “8:30 Calvin”, if you will, is you in the present. All it knows is whether or not you are having a good time in the moment. The remembering self, or “6:30 Calvin”, on the other hand, looks back and tries to to sum up your overall impressions of past events.

Which Calvin holds more sway in your judgements?  That prize goes to 6:30 Calvin. It makes a certain amount of sense. The trouble with living “in the now” is that every second is a different now. Your in-the-moment perceptions are in constant flux. Your remembering self, on the other hand, is a much more fixed point. Besides, the vast majority of the information in your head is not things you’re discovering in the moment; but feelings and data you’ve gradually built up over your whole life.

Unfortunately, 6:30 Calvin doesn’t always know what he’s talking about.

In the past, we’ve discussed the peak-end rule, where our take-home memory of an event puts way too much weight on the most extreme moment, and also on whatever happened at the very end. (Every stage actor knows that you have to bring your A-game to the final scene.) Our most recent recollection can color the rest of our information to a hilarious degree. In one study, people were asked to judge their own life satisfaction. But first, they had to make a photocopy. Half the participants then “discovered” a carefully planted dime in the photocopy room. The simple minor victory of having just gained a free ten cents had a noticeable impact on how they assessed the overall happiness of their lives.

Then, there’s duration neglect. 6:30 Calvin has no way to accurately record time.

To see these effects in action, we need look no further than Kahneman’s “cold hand” study.

First, experimenters asked people to plunge their hand into very cold water for 60 seconds. As you might imagine, this is not the most pleasant activity. (From an experiment design setup, it’s a good way to administer an easy-to-measure but harmless pain. From a “bored scientists hanging around the lab” setup, it’s probably also a decent dare.)

The subjects were allowed to briefly warm and dry their hands with a towel, and to presumably take a moment to ponder the sacrifices we all make for scientific knowledge, and whether or not it’s worth it to hurt yourself on purpose while some schmuck or schmuckette stands over you with a clipboard.

Then, it was back into the cold water. This time, the subjects got 60 seconds just as before, but immediately followed by 30 seconds in water that was exactly one degree warmer.

Told they had to undergo one more dunking, the subjects then had to decide: did they want to relive Option A or Option B?

Keep in mind: Option B is just Option A with 30 extra seconds of slightly less-painful pain. (A total of 90 seconds in cold water.) So surely it will come as no surprise to know that people overwhelmingly chose…Option B. They were swayed by the recollection of the pain lessening of the last 30 seconds (hello, peak-end rule), and while each second in the cold water had probably felt like an eternity as it was happening, the remembering self couldn’t make the distinction.

The remembering self doesn’t care about 60 seconds vs 90 seconds. “What’s the difference to me?” says the remembering self. “I’m talking to you from the past, and in the vast scheme of your life, 30 seconds are nothing.” Sure, it means a little extra pain in the moment, but the remembering self doesn’t worry about the moment. “Not my department,” says the remembering self with a shrug, passing the buck in a scene familiar to anyone who’s ever worked in a company with multiple employees. “It’s someone else’s problem.”

Unfortunately for you, that “someone else” is…your experiencing self.

If you’ve read the classic Calvin and Hobbes strip above, you know that what follows is a whole lot of arguing. Just one more peril of time travel…



Six Strategies for Avoiding the Truth

Are you lying to yourself every day?

Depends: are you a “Bayesian Updater?” Hopefully you are. The term is named after Reverend Thomas Bayes. Around 1763, Bayes proposed a probability theory which stated that when you’re confronted with facts contradicting your current beliefs, you change or update your beliefs.

In his new book, Answers for Aristotle, University of Chicago’s Massimo Pigliuuci suggests that if humans are rational, then the Bayesian principle should be our default. Of course, modern science has done a great deal to de-emphasize the role of logic in decision-making. Even the great philosopher Aristotle, upon closer reading, suggests we are more rationalizers than rational.

So if people aren’t Bayesian Updaters, what are they? In their study of cognitive dissonance, Northwestern University professor Monica Prasad and her research team have identified six alternative strategies. Their work shines on light on just how intelligent and well informed individuals can cling to a belief even in the face of all available proof to the contrary.

Her findings are based on a study about Republicans who failed to change their stance on the Iraq War, even after being confronted with hard evidence that Sadam Hussein was not connected to 9/11, as Bush had initially argued.

Here are the six most common responses Prasad identified in her study:

1. Attitude Bolstering (33%): When told Sadam Hussein had nothing to do with 9/11, this group simply shifted to other justifications for the Iraq War. For example, “There is no doubt in my mind that if we did not deal with Saddam Hussein when we did, it was just a matter of time when we would have to deal with him.”

2. Disputing Rationality (16%): Having trouble justifying your reasoning? Here’s one option: don’t even try. As one subject put it, “Well, I bet they say that the Commission didn’t have any proof of it but I guess we still can have our opinions and feel that way even though they say that.”

3. Inferred Justification (16%): Some respondents worked backwards, suggesting that even if they couldn’t find a reason, surely one had to exist, because why else would we be in Iraq? “…I believe that [the death of innocent people is wrong] also, but there must be a reason why we’re still over there or we wouldn’t be over there still.”

4. Denial of belief in the link (14%): These subjects used a “slippery slope” defense, subtly reinterpreting the original linkage between Hussein and 9/11 to be about Afghanistan and 9/11, as if the malleability of the facts was not a problem.

5. Counter-arguing (12%) Another common strategy was simply refuting the information. These people responded with their own arguments connecting Sadam and the 9/11 attacks. For example, “I believe he was definitely involved with in it because he was definitely pumping money into the terrorist organizations every way he could. And he would even send $25,000 to somebody who committed suicide to kill another person, to their family.”

6. Selective Exposure (6%) Instead of changing their mind, this group simply disengaged from the issue altogether, saying things like, “I don’t know. I don’t know anything about . . . where and what we’re going after.” and “I’m gonna pass on this one, for now.”
Interestingly, even after the subjects were shown a quote where George Bush acknowledged that there was no linkage between 9/11 and Sadam Hussein, only 2% of those surveyed changed their minds.

It should be pointed out that this study is not a condemnation of Republicans. No personal background or political affiliation makes you immune to these fallacies. It’s not an issue of party lines, it’s an issue of being human.

So what drives our cognitive dissonance? One answer might be heuristics. These are the shortcuts, or rule of thumb processes our emotional brains use to make quick decisions. This primitive thinking system (what Daniel Kahneman calls System 1) is alive and well today. We use it on a daily basis. Heuristics are a handy way to solve a problem when time and/or energy are in short supply. The problem starts when we take the shortcut without even knowing it.

Kudos to the Reverend Bayes who, back in the 18th century, gave us the benefit of the doubt when it came to rationality. Today, we have some rather more unflattering facts to face.

That is, if we want to.