Category: People

Samuel Arbesman, Interview No. 1

Samuel Arbesman is an applied mathematician and network scientist. His recent book, The Half-life of Facts, explores how much of what we think we know has an expiry date.

Samuel, who was happy to be the first in an ongoing series of interviews, talks about his book, science, knowledge, and society.

A friend of mine, Neil Cruickshank, helped come up with some of the questions.

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Can you tell me a little bit about your background?


I began my training in evolutionary biology and I received a PhD in computational biology from Cornell University. However, even during graduate school I began to think about how to use the computational and mathematical models I had been learning about to help understand society. This transition continued when I did a postdoctoral fellowship at Harvard under Nicholas Christakis, where I explored social networks, cooperation, and scientific discovery. About two years ago I moved to Kansas City to be a Senior Scholar at the Ewing Marion Kauffman Foundation, where I study and write about a lot of different topics, ranging from the future of science to how cities grow and develop.


What was the motivation behind writing The Half-life of facts?


I’ve always been aware of the huge amount of information that we learn that becomes out-of-date rather quickly. But as I moved into the field of quantitative social science, and explored topics from network science to scientometrics, I realized that there is a deep order to how knowledge grows and changes over time, and even how it spreads from person to person. I wanted to tell this story in the hope that a reader will find it as fascinating as I do, but more importantly, would come away with a deeper appreciation and understanding of the underlying regularities behind all of the knowledge change we see on a daily basis.


… When I read about cognitive biases and also the research that suggests for some areas of expertise – such as medical surgery – at a certain point of time the accumulation of experience does not equate to better performance results, I think about how we often defend our opinions and decisions on the basis of our experience, but in fact that experience may just be a reinforcement of error or bias.

In your book, you supply additional reason for me to doubt even those things I may be very sure of. How do you see the connection between the half-life of facts and what this means to the idea of wisdom and the respect we offer to an individual’s experience?


It’s certainly true that many of the bits of information we learn over the years become outdated and are overturned, and so we have to make sure that what we are working with is not obsolete. And on the basis of this, experience might be a hindrance. But I think a lifetime of experience and wisdom, rather than simply an accumulation of facts, can often leave someone better prepared for dealing with change. Because they’ve had to deal with so much change throughout their lives, people often have a better sense of the shape and impact of change. While it is certainly true that someone with more experience might also be less likely to change their ways, and adhere to outdated information, understanding the regularities behind change—even if only known in an intuitive qualitative sense due to experience—can provide a mechanism for adaptation.


When I read your book I often reflected on moments when I have been sure, and confident. And I also thought about how I have managed being in time of change. In psychology, one of the “big five” personality traits is Openness. Some of us seem to be much more comfortable with flux, or change, and readily able to respond to and even gain energy from change. Others seem to have a greater need for anchors and continuity with the past, and as the degree of change increases we focus more on and more on the things that remain unchanged, and change itself is fatiguing and depressing. Is there a fundamental disadvantage for those of us who are less open and more at ease with stability?


In a word, yes. People who cannot deal with change are going to be at a huge disadvantage in the world. These type of people might not have been disadvantaged in previous generations, where change proceeded rather more slowly, but as the many fundamental changes around us—in what we know and in what the world likes—continue to accumulate, we often have to deal with large numbers of these changes in a single lifetime. In the book, I chronicled the large number of computational information storage technologies (ranging from floppy disks to the Cloud) that I have used over the course of three decades, which is a far cry from the one or two that people of the Middle Ages might have used for storing information (books and scrolls). Those who can’t adapt will have a great deal of trouble in this world.


You quote John H Jackson: “It takes 50 years to get a wrong idea out of medicine, and 100 years a right one into medicine.” I’ve heard teachers say similar things about changes to curriculum. Do you have any thoughts on how education and educators, particularly in schools, should incorporate your ideas into teaching and curriculum design?


This is a really important question. I think that we need to move from an educational system that is focused on memorizing facts to one that is focused on how to learn. Of course you need a fundamental background and familiarity with certain information in order to have a basic understanding of the world, so I wouldn’t throw out memorization entirely. But so much of what we know is going to change and we need to have an educational system that recognizes this. In medicine, there is continuing medical education—constantly learning what is new in one’s field—and I think this kind of attitude needs to be universalized for knowledge in general. Specifically, students need to be taught how to continue to learn new facts, and embrace the changing knowledge around them. If that is the focus, rather than the facts themselves, education will be more durable, but will also create graduates that can continue to learn on their own and adapt the world around them


What about organizations… in a world of constant change how can understanding how facts change better prepare us for dealing with uncertainty?


Organizations often adapt slowly, just like many of us, sometimes even maintaining a mission after it has outlived its usefulness. A willingness to confront these changes must be deeply embedded within the leadership of the organization, which hopefully will be easier when people are educated to understand changing knowledge. Otherwise, the organization will slowly fail, hemorrhaging the more adaptable people—who are frustrated by the lack of change—along the way.


I was struck by your statement: “ONE of the most fundamental rules of hidden knowledge is the lesson learned from InnoCentive: a long tail of expertise— everyday people in large numbers—has a greater chance of solving a problem than do the experts.”

I imagine trying to promote this idea in an organization, such as an IT firm or a Government Department – where there is a strong culture of respect for expertise – and I think it would be an extremely hard sell. If I can be extreme, this idea argues that credentials or other normally recognized markers of individual status are maybe not worth as much, or perhaps overvalued. Do you have any comments on how the idea of “the long tail of expertise” can actually function in a domain where expertise is part of the status and hierarchy?


I think expertise is still important for many questions, especially ones that can be solved in a relatively straightforward manner. But as we move into an increasingly complicated and interdisciplinary world, the expertise we value with likely shift: we will move from valuing those who can solve problems, to those who know different ways to solve problems, or at least those who know how to ask the right questions of a large crowd. Using InnoCentive, or other way to crowdsource expertise is by no means trivial, and understanding the ways that they succeed, as well as the many ways that they can fail, is going to become more important.


How important of a role does diversity play in all of this? If we all goto the same training and schools, and we’re all taught to look at the problem the same way, to what extent would this impact the long tail?


Diversity is critical. We don’t want everyone to have the same background and information. At the same time, making sure that we have people who can bring together diverse backgrounds, translating from one field to another—even at the level of jargon—is also crucial, and something that we often neglect in our excitement of the power of intellectual diversity.


For the most part, I find the tone of your book to be very positive and optimistic – a message of affirmation of the value of trying to understand and learn. But I also note your observation in the Chapter “The Human Side of Facts,” where you describe how we seem to come to a point, often quite early in our lives, where we cease to learn. I observe this often, how we feel there is a sense of having learned and after that learning, life- professional life – is really just the application of learned knowledge. I don’t see a great commitment to “lifelong learning” in North American society, certainly not between the ages of, say, forty and retirement. But professional people often have their greatest influence on the rest of society at this age. Do you have any thoughts on what your ideas imply about lifelong learning and personal development, particularly for those of us who are well-established in our professional careers?


As I mentioned earlier, I think we need to take a page from medicine and its devotion to continuing medical education. Of course, there is a clear incentive in this field, as lives are on the line. But If we can find ways to better incentivize continuing education for everyone, we’ll be a better society. Frankly, this is a hard thing to do. If we can teach students at an early age about the obsolescence of their knowledge, this task will be easier. But for now, it’s quite daunting.


Changing gears a bit… What authors have your learned the most from and why?


I’ve learned a great deal from the novelist Neal Stephenson. His books are generally a set of fascinating ideas wrapped around an engaging plot. The plots pull you along, and in the process I’ve learned about—and been forced to think deeply about—the Scientific Revolution, the invention of the modern monetary system, mathematical platonism, the relationship between Greek mythology and the history of technology, and much more. If you need your mind expanded, Stephenson will deliver.

I’ve also gained a lot from Steven Johnson, who has written many fascinating “idea books” (this term doesn’t quite satisfy me but it’s hard to think of a better description). His ability to weave together numerous concepts that often seem unrelated on the surface and then convey them in a coherent and exciting way is something that is incredibly rare and wonderful to experience.


Do you have daily writing ritual?


I unfortunately don’t have much in the way of rituals. Essentially, I set myself a low word count goal for the day (the amount varies based on how much writing I need to achieve). And then I exceed it. That way, I always overachieve and feel good about my writing for the day. And once I’ve gotten a whole lot of quantity, I then pare it down and do my best to turn it into quality.


Say I’ve anointed you as dictator. What five books would you make every adult read?


This certainly sounds like an intriguing dictatorship. Rather than focusing on my favorite books, I’ll try to limit this to five books that I think are important for thinking about science, knowledge, and society:

Little Science, Big Science by Derek J. de Solla Price — the foundation for a rigorous and quantitative approach for thinking about how science works.

Collected Fictions of Jorge Luis Borges — Interested in thinking about knowledge and infinity? The stories of Borges are essential reading.

Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter — from computer science to how the mind works, this book will change how you think about the world of information.

Nonzero by Robert Wright — a wonderful exploration of how the world has become more complicated and better over time, improving each of our lives

The Varieties of Scientific Experience by Carl Sagan—Sagan’s examination of the complexity of the universe and his personal approach to religion as scientific awe

And an optional bonus book for my dictatorship:

How I Killed Pluto and Why It Had It Coming by Mike Brown — captures the excitement and process of science. It’s also a great story.

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Hetty Green — The Richest Woman In America

Hetty Green knew a thing or two about making money. “A millionaire a hundred times over, she made made her mark beside Carnegie and Morgan, Vanderbilt and Rockefeller.”

Oh yea, and she did this in an era when women were traditionally excluded from all business dealings.

Janet Wallach’s biography of Green, The Richest Woman in America: Hetty Green in the Gilded Age, tells the story of her extraordinary life. Hetty’s principles, on life and investing, are as relevant today as they were during the late 1800s

“Never losing faith in America’s potential, she ignored the herd mentality and took advantage of financial panics and crises. When everyone else was selling, she bought railroads, real estate, and government bonds. And when everyone was buying and borrowing, she put her money into cash and earned safe returns on her dollars. Men mocker her and women scoffed at her frugal ways, but Hetty turned her back on them and piled up her earnings.”

“Cash combined with courage in a crisis, is priceless.” — Warren Buffett

Hetty had a way of stirring the pot, much the same way as present-day billionaire Charlie Munger. Her reputation for harshness was based on her independence, outspokenness, and disdain for the upper crust of society.

“She was,” writes Janet Wallach, “a woman alone in a world of envious men.” And she certainly wasn’t going to follow the men.

Everyone but Hetty seemed to be buying. She did not buy industrials, she said, and never bought with borrowed money. Once in a while she cornered a stock like Reading Railroad, but that was the exception, not the norm. “I don’t believe in speculating as a rule, and I don’t speculate as much as people think.” Her approach was far more cautious: “When good things are so low that no one wants them, I buy them and lay them away in the safe; when owing to some new development, they go up and my shares are so needed that men will pay well for them, I am ready to sell.”

Hetty experienced several financial panics during her lifetime. She believed they offered valuable lessons for the future: “exaggerated expectations, wild speculation, and high leverage would lead to disaster.”

Indeed, Hetty’s wisdom was well ahead of its time:

“There’s one reason why we have hard times: money easy coming and easy going. American children are not taught how to save money but how to spend it. Everything they want—give it to them so long as you know the price of the credit. That’s the policy of the modern mother and she is raising a nation of spendthrifts whose one thought is to get what they want when they want it.”

The wisdom of Hetty Green is as relevant today as it was during her time.

Before deciding on an investment seek out every kind of information about it.

Watch your pennies and the dollars will take care of themselves.

After your business is over you may take your colleague to dinner
and the theater, or allow him to take you, but wait until the
transaction has been closed and the money paid.

Before making a deal, if anyone is fool enough to offer you the
full amount, take it. If you are offered less, tell the man
you will give him the answer in the morning.
Think the matter over carefully in the evening. If you decide that it
will be to your advantage to accept the offer, say so the next day.

In business generally, don’t close a bargain until you have
reflected on it overnight.

The secret of good nursing is common sense, just as common sense
is the secret of making money.

What man has done, women can do.

It is the duty of every woman to learn to take care of
her own business affairs.

An ordinary gift to be bragged about is not a gift
in the eyes of the Lord.

Some young women do better in business than men.

A girl ought to be careful about the man she marries,
especially if she has money.

A girl oughtn’t to marry until she’s old enough to
know what she’s doing.

When good things are so low that no one wants them, I buy
them and lay them away in the safe; when owing to some new
development, they go up and my shares are so needed that men
will pay well for them, I am ready to sell.

I am always buying when everyone wants to sell,
and selling when everyone wants to buy.

If one can buy a good thing at lower cost than it has ever sold for
before, he may be fairly sure of getting it cheap.

Every girl should be taught the ordinary lines of
business investment.

Railroads and real estate are the things I like.
Government bonds are good, though they do not pay
very high interest. Still, for a woman safe and low
is better than risky and high.

Common sense is the most valuable possession
anyone can have.

Jeff Bezos on Why People that Are Often Right Change Their Minds Often

Jeff Bezos recently stopped by the office of 37 Signals. After talking product strategy he answered some questions.

In his answer to one question he shared some thoughts on people who were “right a lot.”

He said people who were right a lot of the time were people who often changed their minds. He doesn’t think consistency of thought is a particularly positive trait. It’s perfectly healthy — encouraged, even — to have an idea tomorrow that contradicted your idea today.

He’s observed that the smartest people are constantly revising their understanding, reconsidering a problem they thought they’d already solved. They’re open to new points of view, new information, new ideas, contradictions, and challenges to their own way of thinking.

This doesn’t mean you shouldn’t have a well formed point of view, but it means you should consider your point of view as temporary.

What trait signified someone who was wrong a lot of the time? Someone obsessed with details that only support one point of view. If someone can’t climb out of the details, and see the bigger picture from multiple angles, they’re often wrong most of the time.

Bezos isn’t alone. Warren Buffett’s long time business partner Charlie Munger captures this:

If Berkshire has made modest progress, a good deal of it is because Warren and I are very good at destroying our own best-loved ideas. Any year that you don’t destroy one of your best-loved ideas is probably a wasted year.

John Kenneth Galbraith put it this way:

Faced with the choice between changing one’s mind and proving there is no need to do so, almost everyone gets busy on the proof.

If you liked this, you’ll love:

How to Change How We Think — In the end changing how we think — that is our thought patterns — becomes about changing the language we use for internal and external communication.

Multitasking: Giving the World an Advantage it Shouldn’t Have — “I think when you multi-task so much, you don’t have time to think about anything deeply. You’re giving the world an advantage you shouldn’t do. Practically everybody is drifting into that mistake.”

Nassim Taleb: The Winner-Take-All Effect In Longevity

Nassim Taleb elaborates on the Copernican Principle, a concept first introduced on Farnam Street in How To Predict Everything.

For the perishable, every additional day in its life translates into a shorter additional life expectancy. For the nonperishable, every additional day implies a longer life expectancy.

So the longer a technology lives, the longer it is expected to live. Let me illustrate the point. Say I have for sole information about a gentleman that he is 40 years old and I want to predict how long he will live. I can look at actuarial tables and find his age-adjusted life expectancy as used by insurance companies. The table will predict that he has an extra 44 to go. Next year, when he turns 41 (or, equivalently, if apply the reasoning today to another person currently 41), he will have a little more than 43 years to go. So every year that lapses reduces his life expectancy by about a year (actually, a little less than a year, so if his life expectancy at birth is 80, his life expectancy at 80 will not be zero, but another decade or so).

The opposite applies to nonperishable items. I am simplifying numbers here for clarity. If a book has been in print for forty years, I can expect it to be in print for another forty years. But, and that is the main difference, if it survives another decade, then it will be expected to be in print another fifty years. This, simply, as a rule, tells you why things that have been around for a long time are not “aging” like persons, but “aging” in reverse. Every year that passes without extinction doubles the additional life expectancy. This is an indicator of some robustness. The robustness of an item is proportional to its life!

This is the “winner-take-all” effect in longevity.

The main argument against this idea is the counterexample — newspapers and traditional telephone lines come to mind. These technologies, widely considered inefficient and dying, have been around for a long time. Yet the Copernican Principle would suggest they will continue to live on for a long time.

These arguments miss the point of probability. The argument is not about a specific example, but rather about the life expectancy, which is, Taleb writes “simply a probabilistically derived average.”

Perhaps an example, from Taleb, will help illustrate. If I were to ask you to guess the life expectancy of the average 40 year old man, you would probably guess around 80 (at least that’s what the actuarial tables likely reveal). However, if I now add that the man is suffering from cancer, we would revisit our decision and most likely revise our estimate downward. “It would,” Taleb writes, “be a mistake to think that he has forty four more years to live, like others in his age group who are cancer-free.”

“In general, the older the technology, not only the longer it is expected to last, but the more certainty I can attach to such statement.”


If you liked this, you’ll love these three other Farnam Street articles:

The Copernican Principle: How To Predict Everything — Based on one of the most famous and successful prediction methods in the history of science.

Ten Commandments for Aspiring Superforecasters — The ten key themes that have been “experimentally demonstrated to boost accuracy” in the real-world.

Philip Tetlock on The Art and Science of Prediction — How we can get better at the art and science of prediction, including diving into makes some people better at making predictions and how we can learn to improve our ability to guess the future.


Happy Birthday Jean-Jacques Rousseau

“Man is born free, yet everywhere he is in chains.”

Jean-Jacques Rousseau was born to a family in Geneva. His mother passed only a few days after his birth. A few years later, his father fled after a duel. At the tender age of 16 he left for France and converted to Catholicism.

At first, he would try to make his way as a musician and composer. After meeting Denis Diderot and Jean d’Alembert in 1740, he became interested in philosophy.

When responding to a competition organized by the Academy of Dijon to answer the question “Has the restoration of the sciences and the arts contributed to refining moral practices?” Rousseau stumbled upon the idea that society might be a harmful influence. Not one to agree with the consensus answer, Rousseau argued the “no” case in his Discourse on the Sciences and Arts, which won him first prize. Far from improving minds and lives, he argued, the arts destroy happiness.

His second essay, Discourse on the Origin and Foundations of Inequality among Men, sowed the seeds for the future by arguing that man is born free.

people are endowed with innate virtue and, more importantly, the attributes of compassion and empathy. But once this state of innocence is disrupted, and the power of reason begins to separate humankind from the rest of nature, people become detached from their natural virtues. The imposition of civil society on the state of nature therefore entails a move away from virtue toward vice, and from idyllic happiness toward misery.

Rousseau sees the fall from a state of nature and the establishment of civil society as regrettable but inevitable, because it resulted from the human capacity for reason. The process began, he thought, the first time that a man enclosed a piece of land for himself, so introducing the notion of property. As groups of people began to live side by side like this, they formed societies, which could only be maintained through a system of laws. But Rousseau claims that every society loses touch with humanity’s natural virtues, including empathy, and so imposes laws that are not just, but selfish.”

(via The Philosophy Book)

These laws, to protect property, were inflicted on the poor by the rich. “The move from a natural to a civilized state therefore brought about a move not only from virtue to vice, Rousseau points out, but also from innocence and freedom to injustice and enslavement.” Humanity, in the eyes of Rousseau, became corrupted by society. Thus while he is born free, the laws imposed by the state ensure he lives his life “in chains.”

As you can imagine this second Discourse caused quite the stir.

Rousseau’s rallying cry of ‘back to nature!’ and his pessimistic analysis of modern society as full of inequalities and injustices sat well with the growing social unrest of the 1750s, especially in France.

Stating the problem was one thing, but in The Social Contract, Rousseau offered a solution. The book opens with the famous quote: “Man is born free, yet everywhere he is in chains.” In time, this would become the slogan for the French Revolution. The solution, argued Rousseau, was to have citizens, not aristocrats, monarchy, or the Church, run the state.

Modeled on Classical republican ideas of democracy, Rousseau imagines the citizen body operating as a unit, prescribing laws according to the volonté générale, or general will. The laws would arise from all and apply to all — everyone would be considered equal. In contrast with the social contract envisaged by Locke, which was designed to protect the rights and property of individuals, Rousseau advocates for the benefit of all, administered by the general will.

He believed that freedom to participate in the legislative process would lead to an elimination of inequality and injustice and promote a feeling of belonging to society.

In the end, Rousseau’s controversial views lead to his books being banned in several countries, including Switzerland and France. Warrants were issued for his arrest. David Hume invited him to live in England, which Rousseau accepted. After a short while a row erupted between Hume and Rousseau and he returned to France under a fake name. At the time of his death in 1778, revolution was imminent.

Key Works:
1750 Discourse on the Sciences and Arts
1755 Discourse on the Origin and Foundations of Inequality among Men
1755 Discourse on Political Economy
1762 The Social Contract

Still curious? Learn more about Rousseau by reading his key works.


Christopher Hitchens: On The Trouble with Causation

From Hitch-22: A Memoir:

In his brilliant book What Is History?, Professor E.H. Carr asked about ultimate causation. Take the case of a man who drinks a bit too much, gets behind the wheel of a car with defective brakes, drives it round a blind corner, and hits another man, who is crossing the road to buy cigarettes. Who is the one responsible? The man who had one drink too many, the lax inspector of brakes, the local authorities who didn’t straighten out a dangerous bend, or the smoker who chose to dash across the road to satisfy his bad habit?

Still curious? Try The Ambiguities of Experience.