The upward spiral is Stephen R. Covey's simple model of personal growth and change, which repeats the three steps: Learn, Commit, and Do.

Of course, we are all doing all of the time. The difference is taking the time and effort to learn from our doing, and deciding to commit to how we want to grow, and deliberately putting it into action. Getting better is in our control.

Though it didn't seem like it would take any effort, I've found the commit step to be surprisingly important. For me, "Commit" means actively deciding to make a change and following through with it. It's the difference between finding something intriguing versus deciding that you're going to do something about it. Coupling the "Commit" with getting specific using, for example, implementation intentions can increase the chance of getting on that upward spiral. "Commit" is the mental shift of telling yourself you're going to make a change.

Repeating each of the three steps again and again is a simple and guaranteed path to improving at anything we try.

Stephen Covey discusses the upward spiral as part of sharpening the saw—renewing, refreshing and recharging ourselves to be the best we can be:

"Renewal is the principle—and the process—that empowers us to move on an upward spiral of growth and change, of continuous improvement."
— Dr Stephen R. Covey

Also see: sharpen the saw, the express-test cycle

The Upward Spiral

The Pyramid Principle is an approach to getting your message across by starting with the main idea supported by the relevant facts or arguments grouped by linking ideas. In this way, the writer clearly makes their point and shows how each idea supports it rather than having the reader try to piece it together as they muddle through.*

As everyone is different, we can't help others draw inferences different than we intend if we present each point in isolation. Instead, leading the reader through by first showing where you're going then raising and answering questions in turn, helps make the reader's life easier.

Barbara Minto, who presented this idea in her book The Pyramid Principle, distinguishes between our everyday approach of thinking through an issue where we often start bottom-up and ultimately get to, or figure out, our main point at the end. While this may be fine for a memo to reschedule a meeting, it's not ideal for an important proposal. Communicating bottom-up makes the reader work harder throughout and risks losing them along the way. Minto advocates doing the work upfront of organising your ideas and presenting them top-down, in a pyramid fashion, to get to the outcomes you want.

Rather confusingly, a related writing technique for journalism is called inverted pyramid writing.

*I first wrote the last sentence here in reverse while thinking through my point: "In this way, rather than having the reader wonder as they go through what point you're making and how the ideas fit together, you have instead done this work for them." Interesting to compare the two.

The Pyramid Principle

VUCA stands for Volatility, Uncertainty, Complexity and Ambiguity.

The VUCA framework is a reminder to consider how to lead and adapt to the challenges of living in a volatile, uncertain, complex and ambiguous world.

In his book Leaders Make the Future, futurist Bob Johansen provides counterpoints to each that leaders can use:

We live in a VUCA world, but we can handle it.

The VUCA framework originated in the US Army War College.

VUCA is an acronym, as opposed to an initialism. Also see OODA Loop.

VUCA

The Overton window is a simple device to consider the full spectrum of policy ideas and identify the range of politically acceptable ones.

Attitudes generally change slowly, as does policy to support them—with exceptions. Ideas that seemed radical or unthinkable at one time may gradually become plausible and popular. As this happens, the Overton Window shifts or expands.

Consider how attitudes have changed towards slavery, segregation, women's rights, animal welfare or gay marriage. Or consider policies made alongside the development of driverless cars or supporting sustainable energy. At one time, prohibition—banning the production and sale of alcohol—was popular enough to become policy in the US, though it would be unlikely to be proposed now.

Generally, the public is unlikely to elect politicians if they stand on policies too far outside the Overton window. And elected politicians will have difficulty enacting policies outside the window.

Named after Joseph Overton of the Mackinac Center for Public Policy, the original model was a cardboard window that could slide over paper, and looking through the window, you could see policy options in one direction towards more government control and in the other towards less government control. He called it the window of political possibilities. The Centre named it after him after his death. He made the slider vertical to avoid associations with the political left or right.

The Overton Window

With well-insulated houses and central heating as standard, I always grew up with heating the space as how you stay warm in the winter. A colleague once shared with me that where he'd lived, they thought of it as heating people, not spaces when looking to stay warm.

The heating people approach means rather than heating the air in the room, you focus on heating the person: warm clothes, hot drinks, baths, cosy furniture with high backs and sides that traps heat in, or furniture that is itself heated like the kotatsu or aga, and generally local heating where a small room or even part of a room may be warm while the rest may be cool — dividing screens are sometimes used.

This approach was common until relatively recently and also still is in countries where it was difficult to stay cool in the summer and houses weren't typically built to keep heat in.

Thanks to Peter Wyatt-Brandenburg for sharing with me many years ago.

Heating people, heating spaces

Maslow's hierarchy of needs, or Maslow's pyramid of needs, was created as the basis for a theory of human motivation by the psychologist Abraham Maslow shared in a 1943 paper. He was interested in what gives our lives meaning and what makes people happy — particularly in the context of a world increasingly driven by consumerism.

He suggested there were our basic needs and our higher level needs — psychological, spiritual, and growth.

In the basic needs you have physiological needs such as not being hungry, thirsty, or cold. Then we have our safety needs such as being free from the threat of violence, or being healthy.

Then we have the higher-level needs of love and belonging including friendship, connection, family. Then esteem needs such as self-respect and self-esteem. And finally our need for self-actualization — reaching our potential, achieving mastery, or being the best we can be.

Maslow continued to refine his original framework. For all its flaws — it always provokes discussion and counter-arguments in my experience — it's remained a clarifying and remarkably enduring model.

If you're designing for needs I prefer Patnaik's hierarchy of needs.

Maslow's hierarchy of needs

Bloom's taxonomy has 6 levels of increasingly sophisticated thinking skills.

It was originally developed in a slightly different form to here for classifying educational objectives and with additional variations, dimensions and sub-levels in the full models, it is useful for informing teaching and learning.

The hierarchy reflects, among other things, that a strong foundation for learning is knowledge.

The 6 levels in the revised Bloom's Taxonomy for learning are:

Bloom's Taxonomy

Where is the Life we have lost in living?
Where is the wisdom we have lost in knowledge?
Where is the knowledge we have lost in information?

In these short lines he touched on an intriguing differentiation between wisdom, knowledge and information. Add data at the beginning and people have proposed various models such as a hierarchy, chain, or pyramid to help understand their relationships.

It's perhaps like a skier who's experienced the data points of snow and conditions in the mountains most days of their life. They begin to observe predictable patterns and then gradually distill these into knowledge of the relationships between the weather and avalanche risk. And over a lifetime of building and applying such knowledge they may develop instincts and behaviours for predicting risk and living with the mountains that may even be called wisdom.

In an unlikely scenario, I once wrote a class paper, that somehow people still find to read, on The Data, Information, Knowledge, Wisdom Chain: The Metaphorical link (pdf). It touches on some of the subtle differences of how we think about each of these, such as how I might complain of information overload, but never of knowledge overload.

Data Information Knowledge Wisdom

The Swiss Cheese Model helps explain why, despite all our best intentions, accidents happen.

Analysis of accidents in large complex systems such as power stations or plane crashes led to an understanding that "no one failure, human or technical, is sufficient to cause an accident. Rather, it involves the unlikely and often unforeseeable conjunction of several contributing factors arising from different levels of the system."

James Reason's Swiss Cheese Model is a memorable visual metaphor that illustrates how each safeguard may contain a latent flaw or hole and that an unfortunate circumstance may result in these holes lining up to disastrous effect. It's also a nice reminder that multiple layers of defence will be more effective, but even with our best efforts, there's still potential for something to go wrong.

Excerpt from Revisiting the "Swiss Cheese" Model of Accidents (pdf), Reason, Hollnagel and Paries, 2006.

Coronavirus example from the Cleveland Clinic.

I learned recently that it's sometimes called the "cumulative act effect".

This sketch, updated and polished, features with a number of others in my book Big Ideas Little Pictures.

The Swiss Cheese Model

This acronym acts as a handy checklist to consider and clarify roles and responsibilities for projects. You could even build a table — a Responsibility Assignment Matrix —  with what needs to happen and the people who are involved identifying what relationship each person has for each task. In particular, sometimes making it clear who doesn’t have a say can be the most helpful thing to do. It breaks down somewhat like this:

Responsible
Who will actually be responsible for doing the task.

Accountable
Who is accountable for it being completed and achieving its goals.

Consulted
Whose opinion will be sought for the task, though they won’t be doing it themselves.

Informed
Who doesn’t get a say in the task, but will be kept informed of how it’s going.

RACI

I hadn’t given much thought to hope, beyond it being a nice feeling to have, until I heard of CR Snyder’s cognitive model for hope which shed a new light on it for me. He proposed a model of hope where (paraphrasing) an individual may be hopeful if they have:

Goals they desire. If you don’t or can’t picture any future state you’d like then you won’t have a lot of hope.

Pathways. You need to see some ways that you may make step-by-step progress towards a goal.

Willpower or agency. You need to be motivated and believe that you have the ability to succeed at your goal.

With all of these you can imagine feeling hopeful. Without any one of them and you probably won’t so much.

The mountain is the Ogre, a wholly impossible looking peak scaled by Doug Scott and others for which I would have had zero hope to climb (no pathways, no willpower) and yet they remarkably did.

HT once again to Brené Brown in Dare to Lead.

Hope

Sexy Value is what you get when someone can launch something that is not only cheaper but also better. It’s a near irresistible proposition.

Most new things that are better don’t tend to also be cheaper—increased quality usually has a corresponding increase in cost. So Sexy Value is often made possible through a new technology or approach. It’s like when the first taxi apps started appearing. To me, the first experience was just so much better than what I was used to—no trying to catch a taxi in the rain, seeing when the cab would arrive and simple, non-awkward, no swinging by the ATM payments—and yet at the same time, it was also cheaper.

Sexy Value is not the only way to compete. If you make something better, people will pay for the value it provides them. But you’re on to a winner if you can also do it cheaper.

Sexy Value is a name, I believe, from Ogilvy and Mather.

You might also like another model of theirs: The Big Ideal

Sexy value

There are lots of questions you can ask of data. I like this model as it gives a framework for the different types of questions you might ask. It was introduced to me as the data science pyramid with descriptive analytics — measuring what’s happening — being the foundation on which others are built. You don’t have to go in order, but it’s a nice approach to consider how the questions you’re asking of your data might evolve.

To take our school Summer fête as an example, for a long time takings were all in cash and put into one bucket at the end for counting. You end up with one number for how much you raised. But you might move to collecting more descriptive data on the takings for each stall — whether the bar earns more than the tombola, for example. You then might be able to ask diagnostic questions like figuring out why one fête earned more than another with a different mix of stalls. If you know how many people came you might be able to make some predictions on the takings of a future fête based on number of people and stall types. And if you get fancy you might start to use your data to figure out how you could raise more money for the school in future.

There are many ways to slice and dice data and the questions you ask, but I like the clarifying simplicity of this one.

As far as I know, the framework is the Analytics Ascendancy model, or Analytics Value Escalator, or other such business sounding name from Gartner.

Analytics maturity

Many of us feel the desire to discover a singular purpose—the one true mission that defines what we should do and where we fit—our ikigai. But perhaps it doesn't have to be that way.

Priya Singh offers a refreshing alternative: Instead of chasing one elusive “why,” recognise that we don't have just one singular purpose and that it can evolve. It’s not a pot of gold or treasure to be found, and we're not failing if we haven't found it.

Three Types of Work: Feeding You, the World and Your Soul

Singh introduces a helpful framework with three types of work:

Work that feeds you and those that depend on you

Your work may fit into one or more of these categories but don’t fall into the trap of thinking it needs to fulfil all three at once.

Rather than striving for the mythical “dream job” that checks every box, embrace the possibility of balance across multiple roles or pursuits.

Rather than striving for the mythical “dream job” that checks every box, embrace the idea of balance across multiple roles or pursuits. Work that fits into just one or two of these areas is plenty—and can be deeply fulfilling.

When faced with opportunities, try shifting your mindset. Instead of asking, “Why do it?” ask, “Why not?” Often, we reject ideas before even giving them a chance.

When presented with an opportunity or an idea, instead of asking why do it, try asking why not—practice not rejecting yourself before you’ve even started.

Framework and wise ideas: Priya Singh. Any misinterpretation or inaccuracy is due to me.

This sketch appears in my book Big Ideas Little Pictures

Discovering Truth and Beauty and Sharing it with Others

Find your why not

The accountability ladder is a framework for taking accountability for a situation in which we can move from a powerless victim mindset to a powerful, accountable mindset.

When something doesn’t go right or something needs doing, there are lots of ways to respond. If you choose a victim mentality, it’s easy to ignore the situation, blame others for it, declare your powerlessness, or just wait and hope. Or you can choose to consider yourself accountable and take a mentality of power where you acknowledge the situation, own it, look for solutions, and take action to do your best.

Bruce Gordon explains the accountability ladder (grainy, slightly odd video) with a fun story about him and his son in which they realise his son has homework due tomorrow that’s not done.

I think most of us have more power over our situations and more potential for impact than we usually give ourselves credit — be that with our jobs, our friends, the environment or local issues. Perhaps considering your position on the accountability ladder is a good place to start.

I love this quote from Erling Kagge, the first person to walk to the triple Poles:

"Most people underestimate the possibilities you have in life. And that’s a bit sad…But don’t underestimate yourself. Also, like I said: Get up in the morning."
— Erling Kagge

There are many versions of the accountability ladder. I couldn’t find a definitive source. If you know, please get in touch.

The accountability ladder

Perhaps, like me, you’re used to thinking about bringing customers onboard as a funnel. It’s a very natural metaphor for thinking about customer acquisition. For example, you market to 10,000 people, 500 people visit your website, 50 of them put something in the basket and 10 of them buy. If you draw it out it looks like a funnel. And the next time you market you start fresh with a new 10,000. But the real world isn’t like that. Delivering a good service to your customers helps the next customers come in. Hence the flywheel model.

A flywheel is typically a big heavy wheel that stores and releases energy from an engine or vehicle. The flywheel metaphor is about happy customers driving your growth. And when you think about your business this way it can cause you to make different decisions. Having more customers is like a bigger, heavier flywheel containing more energy. Happy customers speed you up, unhappy customers slow you down. Making it easier for customers to try your product reduces friction, as does making it easier for for customers to talk about and share your product. Get your flywheel big, heavy and spinning like crazy and your business is doing well.

The flywheel model is from Brian Halligan at Hubspot. I’ve thought about customer funnels for literally years and I wish I’d known about the flywheel long ago. Check out Hubspot’s flywheel intro for more.

The business flywheel

The Fun Scale categorizes different types of fun experiences into distinct levels. It consists of three main types of fun: Type 1, Type 2, and Type 3. The concept behind the Fun Scale is that not all fun is created equal, and some types may be more rewarding or memorable than others.

My brother, who learned it from a mountain guide, introduced me to the Fun Scale. Before then, I used to think that fun was just fun. But the Fun Scale opened my eyes to the fact that there are levels and types of fun, each with its own characteristics. 

So, what are the three types of fun in the Fun Scale?

Type 1 fun is the most straightforward type of fun. It’s the kind of activity that is fun while you’re doing it, and it stays fun when you think back on it. Picture something like eating ice cream on a hot day, riding a roller coaster, or skiing with lifts to whisk you right back to the top. Type 1 fun is carefree, pleasurable in the moment, and provides uncomplicated enjoyment.

I'm sure you can think of a million more.

Type 2 fun: hurts a bit to do, but fun in retrospect

On the other hand, Type 2 fun is a bit trickier. It's the kind of activity where you may not have a blast while you're doing it—it's probably hard work or even painful. However, once it's over, you look back on it with a sense of achievement, and it becomes fun in retrospect.

This is the sort of enjoyment you get from something like running a marathon or climbing a mountain. At the time, you might question why you're doing it. Brendan Leonard in Ultra-something relates the joke, "You know what I like most about climbing a mountain? It feels so good when I stop."

You'll often think of Type 2 fun as ultimately more fulfilling and often somewhat addictive than Type I fun.

Cycling a mountain stage of the Tour de France

Cold water swimming (or maybe an ice mile)

Type 3 fun: not fun to do, not fun in retrospect, but makes a great story

Type 3 fun is usually type 1 or 2 fun that went wrong. Though it was supposed to be fun, things actually got a little hairy. Perhaps a trip started out like good Type 2 fun, but then you got lost, or it got dark, and it got cold, or things got much more serious than intended. Maybe you had to be rescued.

This kind of fun is not fun while it's happening. It's probably not even fun when thinking back on it. But Type 3 fun sure makes a great story when you make it back, and, well, life is made up of great stories, so perhaps it wasn't so bad after all.

Not practicing your kitchen table survival skills

There are rumours of Type 4 fun and Type 5 fun, but having heard some good stories of Type 3 fun and created a few myself, I can't say I recommend them =)

The Fun Scale, adventure and fulfilment: why we crave Type 2 and Type 3 fun

In our podcast discussing the Fun Scale, Tom, identified Rob and I as Type 2 Fun junkies. There's something intriguingly addictive about setting yourself difficult challenges, pushing through hardship, and emerging out the other side. Rob and I have signed up for a challenging endurance event pretty much every year for the last decade or so. Every single time the event on the day is really hard. And yet, once the immediate memories subside we find ourselves signing up for something similar next year.

Even if it's not you, I'm sure you probably know someone who seems to keep pushing themselves to do things that they don't seem to enjoy. It reminds me of Calvin imitating his dad in Calvin and Hobbes: "Calvin, go do something you hate! Being miserable builds character!"

Type 2 fun and type 3 fun, to some extent, help build character, life experiences and the stories that shape us and are fun to tell others. The sense of accomplishment and unforgettable stories that emerge from these experiences outweigh the discomfort in the long run.

Type 1 fun is fun when you do it and fun to remember.

Type 2 fun is not so fun when you do it, but it is fun in retrospect and is the most fulfilling.

And Type 3 fun is not fun in the moment or when you remember it—but it makes the best stories!

I have seen people write about Type A fun, Type B fun and Type C fun, or Type I fun, Type II fun and Type III fun, but I learned it as 1, 2 and 3.

The Fun Scale is probably my favourite idea that didn't make it into my new book. If you like this one, you'll love the book Big Ideas Little Pictures.

Kaffikok - the distance you can go before needing a coffee

The fun scale: understanding the types of fun

I like this simple idea that evidently illustrates that anything that is able to improve, learn, and grow at a faster rate than something else stands a decent chance of making up lost ground pretty quickly. Consider this when you’re hiring, or when you’re worried that some other person or company has got a headstart on knowledge. Position yourself always as the fastest and most persistent ‘improver’ and you’ll stand a chance whatever you’re doing.

Read the full story of Stanford Professor John Ousterhout’s thought for the weekend: a little bit of slope. 

A little bit of slope makes up for a lot of y-intercept.

Even when you’ve figured out how family relations work, families, in just a few generations, can get surprisingly complex. I won’t pretend this one doesn’t require a little study.

What is a first, second or third cousin? And what does once or twice removed have to do with anything? One way to think about it is that the first, second or third cousins, have to do with the number of generations you are away from a shared ancestor. So, who you would probably normally call your cousins — your parents brothers or sisters, children — have one generation, your parents generation, before reaching grandparents that are shared by both. If you have children, and your first cousins have children, they will be second cousins to eachother as it’s now two generations to a shared ancestor — their great grandparents in this case.

While first, second, or third cousins of eachother are of the same generation, when you are once removed it means you are cousins one generation apart. So, you would be first cousins once removed with your cousin’s children. If you look at the sketch, you’ll actually see that you are second cousins once removed with your parent’s cousin’s grandchildren. Simple ¯_(ツ)_/¯

The sketch gets pretty complicated to see this, and that’s without even showing having more than one sibling, any of the in-law families, or considering divorces, remarries, half-brothers, step mothers and the like. Crikey.

Second cousins once removed.

Two-factor authentication is a neat technique for adding extra security by requiring two different types of verification. So, rather than asking you to provide two passwords—both things you could remember or find written down—if you are asked to provide a password and a code you could only have if you had a particular device, security is greatly enhanced.

The usual factors involved include asking for two from:

Hence the convenience of photo ID where you have to provide the ID and also look like the photo. Or provide a ticket and a code, or a chip and pin…

Also see: choose passwords that make you happy, and 8 character passwords

2 factor authentication

This one rewards a little close attention—looking at each of the words and figuring out their different meanings or sounds.

I’ve always loved heteronyms and how we can have a single word spelt the same and yet pronounced quite differently — like read — and how that clearly makes English a crazy language to learn. And, as you probably do too, I pretty much woke up at night thinking how you could sort words into groups of the same or different spelling and the same or different sounds and begin to make sense of these curious groups of words like homographs, homophones and heteronyms.

Words with different spellings and different sounds generally just mean different words.

There are nice buckets of other words too, like, contranyms — words that can be their own opposite. And also aptronyms (good for nominative determinism).

I did think a third axis of the same or different meaning may give the complete picture but would probably just serve to confuse things.

Some Greek: homo—same, hetero—different, graph—written, phone—sound

Mad props to the incredible poem The Chaos by Gerard Nolst Trenité. The poem gives an amazing number of examples of some of the craziness of the English language. Here's an excerpt from the start:

Dearest creature in creation
Studying English pronunciation,
   I will teach you in my verse
   Sounds like corpse, corps, horse and worse.

I will keep you, Susy, busy,
Make your head with heat grow dizzy;
   Tear in eye, your dress you'll tear;
   Queer, fair seer, hear my prayer.

Pray, console your loving poet,
Make my coat look new, dear, sew it!
   Just compare heart, hear and heard,
   Dies and diet, lord and word.

Sword and sward, retain and Britain
(Mind the latter how it's written).
   Made has not the sound of bade,
   Say-said, pay-paid, laid but plaid.

Now I surely will not plague you
With such words as vague and ague,
   But be careful how you speak,
   Say: gush, bush, steak, streak, break, bleak...

Homonyms, homographs, homophones, heteronyms… 

Networks effects can lead to massive, rapid growth especially if you manage to get a virtuous cycle turning.

Amazon leveraged this model by Jeff Bezos in 2001 for mega growth. Amazon calls it a virtuous cycle (and some call it a virtuous circle). And, more recently, the Uber variation, by David Sacks explains much of Uber’s wild ride. The virtuous cycle is a form of flywheel where once it gets going it keeps on spinning.

When you build a platform that leverages network effects in the right way it can enable growth way beyond what has historically been possible.

Also, see Metcalfe’s Law, the business flywheel, exercise and sleep

The ‘Virtuous Cycles’ of Amazon and Uber

The OODA loop is military strategist John Boyd’s framework for combat operations that also turns out to apply quite well to businesses and learning in general. It emphasizes a rapid cycle of Observing, Orienting, Deciding and Acting.

Though it’s not so different from the classic test-learn cycle or a good design process, Boyd’s framework has a lot of nuances. I found applying it to my own life valuable because:

The faster you can do this loop—in your work or in a conflict of any kind—the more solutions you can try and the quicker you will learn.

If you’re competing against others, completing your OODA loop fast and acting to change the environment for them means you can disrupt their loop and force them back to the observation step before they can act. It slows them down, creates confusion and gives you an advantage.

To apply the OODA loop to a business context, it can help to reconsider the points on the cycle as Frame, Strategize, Test, and Gather.

I learned about it from Reid Hoffman’s excellent Masters of Scale podcast.

The OODA loop features in my book Big Ideas Little Pictures

My original OODA loop sketch was an animation

OODA Loop

A handy journalist technique whereby you write in such a way that even a cursory glance at an article gives the key facts, and the further you read down you increase your knowledge with the next most important facts. As opposed to say, a chronological account of an event where the important stuff may be at the end. The BBC at least are great examples of this, for instance in a Premier League match write-up.

Given how people read on the web generally, it’s pretty good to keep in mind for anything you write on the web too.

Also see: the best writing is rewriting, front load names to cue attention

Inverted pyramid writing

Simon Sinek’s simple idea to start with why. To get a better feel, watch his 18min TED talk: How great leaders inspire action. I found his concrete example of “It was the ‘I have a dream’ speech, not the ‘I have a plan’ speech,” helps keep in mind the power of starting with why and painting a vision in order to inspire and lead. Now, if you have a vision, a strategy and a plan, well, then you’re in business.

People don’t buy what you do, they buy why you do it.
— Simon Sinek

Simon’s has parallels with another I like:

Products aren’t just things that you buy, they’re things that you buy into.

The golden circle

I like this simple model of self-awareness and understanding your relationship with others. Some things only others can see about you, and to learn about these you need feedback. While others may not realise some things you know about yourself — by sharing or disclosing more, you help others understand more about you. And still other aspects about you, particularly when you are young, may remain unknown to you and others.

Depending on who you’re with, the relative size of each quadrant may be different, for example, if you start on a new team at work.

The examples in the quadrants are as shared with me by Nicola Rowledge.

Johari window — a window of feedback and sharing

How the expectations of new technologies often evolves.

The Gartner Hype cycle

These days beards are in. There will come a day when beards are out. And a day when beards are back in again. That’s how it seems to go.

Turns out there is a name for this kind of thing: negative frequency-dependent selection. Essentially, the less common it is, the more useful a trait it is. As opposed to positive frequency-dependent selection which, as you can imagine, is the reverse.

According to this study, for example, when there are fewer men with beards in a population, they are judged as more attractive than when there are more of them. Hence they become gradually more popular until the effect starts to wear off and the clean-shaven look starts to appeal again. And round the cycle we go.

The beard cycle

Strahler stream order is a smart way of categorizing the size of rivers by tracking where tributaries join. 

Each time two tributaries of the same order join together, the river rises in order.

So, the start of a stream from a spring is the outermost branch—it's first order. When two first-order tributaries join together, the river is classified as second-order, and so on.

The largest river by Strahler stream order classification is the Amazon, which is an incredible 12th-order river. This means that at least two 11th-order rivers had to merge together before the river emptied into the sea. Huge.

Strahler stream order: Streams, rivers, the Amazon and how to organise them.

I’ve found this model useful in my thinking so many times. Also known as the Buying Hierarchy, it’s a model that illustrates a common evolution — though not perfect nor universal — in products and markets where an original innovation provides a performance or functionality benefit over what others can provide. As a result they can charge more as no one else does it.

When others come to deliver that too, then the focus for the customer can move to which delivers the most reliable quality. When the reliability is the same from different providers then we’ll choose the one that is more convenient.

Framework sketches