Age and the entrepreneur, part 1: Some data

A short time back, several smart bloggers engaged in an enthusiastic debate about age and entrepreneurs – some taking the position that kids have a leg up on older entrepreneurs at least for certain categories of startups, and others theorizing that age is largely irrelevant (or as Ali G would put it, “geezers is good entrepreneurs as well, man”).

I have opinions on this topic, but rather than just mouthing off like I would normally do, I decided to go get some data. This post presents that data – the next post will have the mouthing off.

I’m not aware of any systematic data on age and high-tech entrepreneurs. As far as I’m aware, all we have are anecdotes. However, a professor of psychology at University of California Davis named Dean Simonton has conducted extensive research on age and creativity across many other fields, including science, literature, music, chess, film, politics, and military combat.

Dr. Simonton’s research is unparalleled – he’s spent his career studying this and related topics and his papers make for absolutely fascinating reading.

For this post, I’ll be concentrating on his paper Age and Outstanding Achievement: What Do We Know After a Century of Research? from 1988. I haven’t been able to find a PDF of the paper online but you can read a largely intact cached HTML version courtesy of Google Scholar.

Let’s go to the paper:

For centuries, thinkers have speculated about the association between a person’s age and exceptional accomplishment: Is there an optimal age for a person to make a lasting contribution to human culture or society? When during the life span can we expect an individual to be most prolific or influential?

You can see why I think this is relevant.

Here we adopt the product-centered approach, that is, our focus is on real-life achievements rather than performance on abstract… measures. …

[A]chievement [takes] the form of noteworthy creativity… the goal is to assess how productivity changes over the life span… [I] focus on individual accomplishment in such endeavors as science, philosophy, literature, music, and the visual arts. …

[Studies like these focus] on three core topics: (a) the age curve that specifies how creative output varies over the course of a career, (b) the connection between productive precocity, longevity, and rate of output, and © the relation between quantity and quality of output (i.e., between “productivity” and “creativity”).

Dr. Simonton also discusses leadership as distinct from creative production, but I’m ignoring the leadership part for now since it’s quite different.

One empirical generalization appears to be fairly secure: If one plots creative output as a function of age, productivity tends to rise fairly rapidly to a definite peak and thereafter decline gradually until output is about half the rate at the peak.

This is the centerpiece of Dr. Simonton’s overall theory across many domains. And is probably not unexpected. But here’s where it gets really interesting:

[T]he location of the peak, as well as the magnitude of the postpeak decline, tends to vary depending on the domain of creative achievement.

At one extreme, some fields are characterized by relatively early peaks, usually around the early 30s or even late 20s in chronological units, with somewhat steep descents thereafter, so that the output rate becomes less than one-quarter the maximum. This age-wise pattern apparently holds for such endeavors as lyric poetry, pure mathematics, and theoretical physics…

The typical trends in other endeavors may display a leisurely rise to a comparatively late peak, in the late 40s or even 50s chronologically, with a minimal if not largely absent drop-off afterward. This more elongated curve holds for such domains as novel writing, history, philosophy, medicine, and general scholarship.

Well, that’s interesting.

It must be stressed that these interdisciplinary contrasts do not appear to be arbitrary but instead have been shown to be invariant across different cultures and distinct historical periods.

As a case in point, the gap between the expected peaks for poets and prose authors has been found in every major literary tradition throughout the world and for both living and dead languages.

Indeed, because an earlier productive optimum means that a writer can die younger without loss to his or her ultimate reputation, poets exhibit a life expectancy, across the globe and through history, about a half dozen years less than prose writers do.

You know what that means – if you’re going to argue that younger entrepreneurs have a leg up, then you also have to argue that they will have shorter lifespans. Fun with math!

You may not be surprised to find that in creative fields, the power law rule – also known as the 80/20 rule – definitely applies:

A small percentage of the workers in any given domain is responsible for the bulk of the work. Generally, the top 10% of the most prolific elite can be credited with around 50% of all contributions, whereas the bottom 50% of the least productive workers can claim only 15% of the total work, and the most productive contributor is usually about 100 times more prolific than the least.

Here’s where it gets really interesting again:

Precocity, longevity, and output rate are each strongly associated with final lifetime output – that is, those who generate the most contributions at the end of a career also tend to have begun their careers at earlier ages, ended their careers at later ages, and produced at extraordinary rates throughout their careers. …

These three components are conspicuously linked with each other: Those who are precocious also tend to display longevity, and both precocity and longevity are positively associated with high output rates per age unit.

OK, so on to the main question, which is, when’s the peak?

Those creators who make the most contributions tend to start early, end late, and produce at above-average rates, but are the anticipated career peaks unchanged, earlier, or later in comparison to what is seen for their less prolific colleagues? Addressing this question properly requires that we first investigate the relation between quantity and quality, both within and across careers. …

This is a very complex topic and Dr. Simonton goes into great detail about it throughout his work. I’m going to gloss over it a bit, but if you are interested in this topic, by all means dig into it more via Google Scholar.

First, if one calculates the age curves separately for major and minor works within careers, the resulting functions are basically identical…

Second… minor and major contributions… fluctuate together. Those periods in a creator’s life that see the most masterpieces also witness the greatest number of easily forgotten productions, on the average.

Another way of saying the same thing is to note that the “quality ratio,” or the proportion of major products to total output per age unit, tends to fluctuate randomly over the course of any career. The quality ratio neither increases nor decreases with age…

These outcomes are valid for both artistic and scientific modes of creative contribution. What these two results signify is that… age becomes irrelevant to determining the success of a particular contribution.

OK, that’s interesting. Quality of output does not vary by age… which means, of course, that attempting to improve your batting average of hits versus misses is a waste of time as you progress through a creative career. Instead you should just focus on more at-bats – more output. Think about that one.

If this sounds insane to you, Dr. Simonton points out that the periods of Beethoven’s career that had the most hits also had the most misses – works that you never hear. As I am always fond of asking in such circumstances, if Beethoven couldn’t increase his batting average over time, what makes you think you can?

[C]reativity is a probabilistic consequence of productivity, a relationship that holds both within and across careers.

Within single careers, the count of major works per age period will be a positive function of total works generated each period, yielding a quality ratio that exhibits no systematic developmental trends.

And across careers, those individual creators who are the most productive will also tend, on the average, to be the most creative: Individual variation in quantity is positively associated with variation in quality.


OK, next step:

[This] constant-probability-of-success model has an important implication for helping us understand the relation between total lifetime output and the location of the peak age for creative achievement within a single career.

Because total lifetime output is positively related to total creative contributions and hence to ultimate eminence, and given that a creator’s most distinguished work will appear in those career periods when productivity is highest, the peak age for creative impact should not vary as a function of either the success of the particular contribution or the final fame of the creator. …

Thus, even though an impressive lifetime output of works, and subsequent distinction, is tied to precocity, longevity, and production rate, the expected age optimum for quantity and quality of contribution is dependent solely on the particular form of creative expression.

Wow, again.

Anyone who demonstrates… an age decrement in achievement is likely to provoke controversy. After all, aging is a phenomenon easy enough to become defensive about, and such defensiveness is especially probable among those of us who are already past the putative age peak for our particular field of endeavor…

I think Dr. Simonton is ready to start blogging.

His paper then goes on to discuss many possible extrinsic factors such as health that could impair later-life output, but in the end he concludes that the data is pretty conclusive that such extrinsinc factors serve as “random shocks” to any individual’s career that do not affect the overall trends.

He then goes on to discuss possible intrinsic factors that could explain a relationship between age and creative accomplishment:

G. M. Beard was not merely the earliest contributor [in 1874] to the empirical literature on age and achievement but its first theorist as well. According to him, creativity is a function of two underlying factors, enthusiasm and experience. Enthusiasm provides the motivational force behind persistent effort, yet enthusiasm in the absence of the second factor yields just original work. Experience gives the achiever the ability to separate wheat from chaff and to express original ideas in a more intelligible and persistent fashion. Yet experience in the absence of enthusiasm produces merely routine contributions. Genuine creativity requires the balanced cooperation of both enthusiasm and experience.

Beard postulates, however, that these two essential components display quite distinctive distributions across the life span. Whereas enthusiasm usually peaks early in life and steadily declines thereafter, experience gradually increases as a positive monotonic function of age. The correct equilibrium between the two factors is attained between the ages of 38 and 40, the most common age optima for creative endeavors. Prior to that expected peak, an individual’s output would be excessively original, and in the postpeak phase the output would be overly routine. The career floruit in the late 30s thus represents the uniquely balanced juxtaposition of the rhapsodies of youth and the wisdom of maturity.


Beard’s theory is not without attractive features… Beard’s account, for all its simplicity, can boast a respectable amount of explanatory power. Besides handling the broad form of the age curve, this theory leads to an interpretation of why different endeavors may peak at distinct ages.

The contrast between poetic and prose literature, for instance, can be interpreted as the immediate consequence of the assumption that the two domains demand a different mix of the two factors: poetry, more enthusiasm, and prose, more experience. Indeed, in fields in which expertise may be far more crucial than emotional vigor, most notably in scholarship, we would anticipate little if any decline with age, and such is the case.

Dr. Simonton, however, then goes on to explain that this theory does not really match the data – for example, the data shows that quality of output in practically all fields does not decline systematically with age, which is what you’d expect from Beard’s theory.

The paper then digs into possible correlations between intelligence as measured by such metrics as IQ, and creative output:

[E]ven if a minimal level of intelligence is requisite for achievement, beyond a threshold of around IQ 120 (the actual amount varying across fields), intellectual prowess becomes largely irrelevant in predicting individual differences in… creativity.

So what have we learned in a nutshell?

  • Generally, productivity – output – rises rapidly from the start of a career to a peak and then declines gradually until retirement.
  • This peak in productivity varies by field, from the late 20s to the early 50s, for reasons that are field-specific.
  • Precocity, longevity, and output rate are linked. “Those who are precocious also tend to display longevity, and both precocity and longevity are positively associated with high output rates per age unit.” High producers produce highly, systematically, over time.
  • The odds of a hit versus a miss do not increase over time. The periods of one’s career with the most hits will also have the most misses. So maximizing quantity – taking more swings at the bat – is much higher payoff than trying to improve one’s batting average.
  • Intelligence, at least as measured by metrics such as IQ, is largely irrelevant.

So here’s my first challenge: to anyone who has an opinion on the role of age and entrepreneurship – see if you can fit your opinion into this model!

And here’s my second challenge: is entrepreneurship more like poetry, pure mathematics, and theoretical physics – which exhibit a peak age in one’s late 20s or early 30s – or novel writing, history, philosophy, medicine, and general scholarship – which exhibit a peak age in one’s late 40s or early 50s? And how, and why?

[Update: Naval Ravikant has written a particularly interesting response to this post here.]

Age and the entrepreneur, part 1: Some data

The Information Machine

A 1957 animated short by Charles And Ray Eames: “Applies graphic sensitivity to medium in cartoon form, and traces the history of storing and analyzing information from the days of the cavemen to today’s age of electronic brains.”

The Information Machine

A Vegan/Aerobicizer Hits the Wall

From Art de Vany’s web site, ca. 2007:

I ran into a guy at the gym whom I had not seen for a couple of months, maybe more.

He was in the gym hours on end (when I used to see him) doing aerobics. He did so much treadmill work that he constantly limped and had a brace on his foot, sometimes on his knee. He had poor posture from walking slumped over looking at the track or the monitor. Nothing in his work outs addressed his posture and his aerobic work only reinforced it. He worked out every day as far as I could tell because he was always there when I came in.

He was a pure vegetarian. He ate a lot of beans and spinach and always told me how fresh he felt from his food. He had no muscle and was a “fat-skinny” jogger or treadmill addict. Sklnny arms, little legs and a bony back.

I was a bit shocked though to see how his appearance had degraded in the few months since I had last seen him. He had gotten quite thick around the waist, but not anywhere else. Still no muscle and a tired, haggard look and slumped posture. At least he was not limping and had no braces on. Rather than ask him if he had been ill, I just asked how he was doing. He really didn’t answer but he did say he had been gone 2 months working on a cabin.

I don’t want to speculate, but it does seem to me that his diet and training make his fitness vulnerable or brittle. He is poised on a razor’s edge in a sense that any small change in diet or exercise sends him down a steep slope. He quickly loses fitness and his body composition quickly fades if he changes either his diet or his exercise. I doubt that his diet changed. So, it is likely his energy expenditures and particularly his peak expenditures that changed. It was easy to see that his insulin sensitivity had declined because all the new weight was gathered in the abdominal area. Maybe he had an illness or went through a major stress. On the other hand, there is seldom a “cause” for human physiology is so complex it is not possible to trace a major change of this magnitude to a single factor.

What I am driving at is that his approach to diet and fitness left him vulnerable. He has to stay on that treadmill or he falls hard. Even on the treadmill, though he managed his weight, he was on the boundary of good health. Not enough nutrition or rest and doing the wrong sorts of exercise. He looked depleted then and even more so now.

I am sorry to see this happen, but I don’t think I can do anything about it. If there is any lesson here it is to adopt a fitness approach that does not leave you vulnerable to damage, poor nutrition, or unusual stress. If you are on the edge in terms of nutrition (either trying to “bulk up” or lose weight or eating a narrow range of foods) or exercise (over training and doing repetitive work outs), you become vulnerable. You are living on the edge. An easy approach mixing intensity, variety, and great food is more healthful and leaves you poised to adapt to stresses that are bound to occur.

A Vegan/Aerobicizer Hits the Wall

Book of the week: Soon I Will Be Invincible

If, like me, you are a fan of the implausibly best show on network television, Heroes, or if you just like fun writing, run don’t walk to Amazon to buy Soon I Will Be Invincible, a novel by Austin Grossman.

An unlikely cross between a spoof and a real novel, the book alternatives between the points of view of Doctor Impossible, supervillain extraordinaire, and Fatale, the newest hero on her first day with the Champions, the world’s most famous superteam. Fatale introduces herself:

Four years ago, I decided to start calling myself Fatale. It’s my superhero name. I chose it from a list they supplied me in the clinic, and at the time it seemed like the perfect symbol for my dangerous, sexy new self, a cybernetic woman of mystery. Admittedly, I was on a lot of painkillers.

Meanwhile, Doctor Impossible is languishing in prison:

I’m not a criminal. I didn’t steal a car. I didn’t sell heroin, or steal an old lady’s purse. I built a quantum fusion reactor in 1978, and an orbital plasma gun in 1979, and a giant laser-eyed robot in 1984. I tried to conquer the world and almost succeeded, twelve times and counting…

I’m the smartest man in the world. Once I wore a cape in public, and fought battles against men who could fly, who had metal skin, who could kill you with their eyes… Now I have to shuffle through a cafeteria line with men who tried to pass bad checks. Now I have to wonder if there will be chocolate milk in the dispenser. And whether the smartest man in the world has done the smartest thing he could with his life.

And they’re off to the races from there.

Book of the week: Soon I Will Be Invincible

Yet another blog-reading refactoring

I started RSS-reading with Bloglines and, though it still has some features I like, I moved to Google Reader last year and have been pretty satisfied with it.

What’s been harder has been managing my blog diet, the number of feeds I read, and the general problems of absorbing so much ephemera. Blog reading takes up an inordinate amount of my time, it seems, even just to glance through the list of postings. I put off writing, practicing, reading books, etc., so I can process a bottomless inbox of blog postings.

I’ve just gone through another fit of downsizing. I have about 50 blogs in Google Reader BUT many of these blogs don’t post daily; some are Ask Metafilter keyword feeds that only appear when a new post appears and others are weekly (like PostSecret) or occasional (and Catarina is on a well-deserved hiatus from the PC).

The two blogs that really distracted me were Marginal Revolution and Lifehacker, so I’ve taken them off the Reader list and will just visit them and browse when I want to. One of the Lifehacker editors mentioned some years back that this was his strategy: no RSS reader, visit bookmarked blogs occasionally or regularly, and he stayed in control of the process.

And for the record, how I process these beasties is like this (borrowed, I think, from Mike Shea, cited in one of the links above):

  1. In Reader, set Start page preferences for “All items.”
  2. Star the items I want to return to later, then select “Mark all as read.”
  3. Display all the starred items.
  4. Use the shortcut keys to move through them quickly, unstar them, Share them (I have my Tumblr log display the shared items), or, if the post is long and I don’t have time to read, email it to my Gmail account.

At the end, there should be no unread items and all posts should be processed, either read or emailed for later reading.

Processing these posts in my Gmail inbox is a different kettle of meat. I have labels set up for each day of the week, and send these new postings to tomorrow’s label. The next day’s job is to process these (read, or set a bookmark, or make a new project, or archive them for reference, or something).

But this week, I’ve been moving unread items from day to day, until now there’s about 55 blog posts that I somehow decided last week I’d have time to process this weekend. And no, I won’t have time to read them all carefully, or even scan them all.

So I’ll set a timer for 30 minutes or so, blow through as many as I can, and then with a heavy heart delete the rest. I have a bad case of “just-in-case” syndrome and, by and large, I never need many of the blog posts I read and rarely do I refer to them when I decide to archive them in Gmail. I’ve decided I want to start the week with a clean slate and not carry over a blog-reading debt from week to week.


James Montgomery Flagg (1877-1960) drew the same way that he lived: brash and arrogant.

Flagg’s confidence was understandable. He started his career at the moment when improvements in the printing process and the rise of popular magazines created a huge market for his drawing skills. Illustrators such as Flagg became national celebrities, and he basked in the attention. His famous poster, Uncle Sam Wants You, made him a household name. The press sought him out for his strong opinions. He consorted with hollywood stars, judged beauty contests, seduced young and impressionable models, frolicked at bohemian parties, and traveled back and forth to Europe with the beautiful people.

I like his work a lot. My biggest complaint is that Flagg rarely let a single well-considered line suffice where five additional lines might fit:

In this way, his style reflected his personality: never waste a minute reconsidering your initial line– just keep underscoring it again and again.

Flagg led a privileged life and had little understanding or sympathy for those who did not. He was a member of exclusive men’s clubs from whose barricades he merrily indulged his sexist and racist attitudes. His invitation to the annual minstrel show at the elite Lotos club in New York is a beautiful painting of an odious subject:

No fan of government welfare programs, here is Flagg’s sketch for the prestigious Dutch Treat Club of the government sodomizing the people.

Life was mighty fine for Flagg. But like many people who happened to be born at the right time, it never occurred to him that luck might have played a role in his success, or that the conditions that catapaulted him to fame might someday change. His pictures that once commanded the public’s attention were eclipsed by Hollywood pictures that moved and talked. Flagg found himself on the wrong side of history. He did not respond well to public neglect, and died a sour and bilious old man. But he left us some terrific drawings from his peak period.


Colin Roberts comments on Back from Holiday


I read your leader on the above with interest. It reminded me of the following experience:

I once worked for a large Insurance company. My boss was a manager who came back off holiday to an inbox of several hundred e-mails.

He deleted them all and then sent a mail to everyone in the company along the lines of

“you won’t believe how stupid I’ve been. I’ve come back off holiday and accidentally deleted all the mail in my in-box. If you sent me anything important in the last two weeks, please resend it immediately”

Result: he got 7 (seven) resent e-mails.

I do admit that this is a tactic which can look suspicious if used too often and probably not a good idea if you get lots of important external e-mails. But it was impressive.



Colin Roberts comments on Back from Holiday