Chapter 1 () Your Professional Decline Is Coming (Much) Sooner Than You Think Who are the five greatest scientists who have ever lived? This is the kind of question people like to debate in nerdy corners of the internet that you probably don''t visit, and I don''t intend to take you there. But no matter how much or little you know about science, your list is sure to contain Charles Darwin. He is remembered today as a man who changed our understanding of biology completely and permanently. So profound was his influence that his celebrity has never wavered since his death in 1882. And yet Darwin died considering his career to be a disappointment. Let''s back up. Darwin''s parents wanted him to be a clergyman, a career for which he had little enthusiasm or aptitude. As such, he was a lackluster student.

His true love was science, which made him feel happy and alive. So it was the opportunity of a lifetime to him-"by far the most important event in my life," he later called it-when, in 1831 at age twenty-two, he was invited to join the voyage of The Beagle, a scientific sailing investigation around the world. For the next five years aboard the ship, he collected exotic plant and animal samples, sending them back to England to the fascination of scientists and the general public. This was impressive enough to make him pretty well-known. When he returned home at age twenty-seven, however, he started an intellectual fire with his theory of natural selection, the idea that over generations, species change and adapt, giving us the multiplicity of plants and animals we see after hundreds of millions of years. Over the next thirty years, he developed his theory and published it in books and essays, his reputation growing steadily. In 1859, at age fifty, he published his magnum opus and crowning achievement, On the Origin of Species, a bestseller explaining his theory of evolution that made him into a household name and changed science forever. At this point, however, Darwin''s work stagnated creatively: he hit a wall in his research and could not make new breakthroughs.

Around that same time, a Czech monk by the name of Gregor Mendel discovered what Darwin needed to continue his work: the theory of genetics. Unfortunately, Mendel''s work was published in an obscure German academic journal and Darwin never saw it-and in any case, Darwin (who, remember, had been an unmotivated student) did not have the mathematical or language skills to understand it. Despite his writing numerous books later in life, his work after that broke little ground. In his last years, Darwin was still very famous-indeed, after his death he was buried as a national hero in Westminster Abbey-but he was increasingly unhappy about his life, seeing his work as unsatisfying, unsatisfactory, and unoriginal. "I have not the heart or strength at my age to begin any investigations lasting years, which is the only thing which I enjoy," he confessed to a friend. "I have everything to make me happy and contented, but life has become very wearisome to me." Darwin was successful by the world''s standards, washed up by his own. He knew that by all worldly rights, he had everything to make him "happy and contented" but confessed that his fame and fortune were now like eating straw.

Only progress and new successes such as he enjoyed in his past work could cheer him up-and this was now beyond his abilities. So he was consigned to unhappiness in his decline. Darwin''s melancholy did not abate, by all accounts, before he died at seventy-three. I''d like to be able to tell you that Darwin''s decline and unhappiness in old age were as rare as his achievements, but that''s not true. In fact, Darwin''s decline was completely normal, and right on schedule. And if you, like Darwin, have worked hard to be exceptional at what you do, you will almost certainly face a similar pattern of decline and disappointment-and it will come much, much sooner than you think. The surprising earliness of decline Unless you follow the James Dean formula-"Live fast, die young, leave a good-looking corpse"-you know that your professional, physical, and mental decline is inevitable. You probably just think it''s a long, long way off.

You''re not alone in thinking this. For most people, the implicit belief is that aging and its effect on professional performance are something that happen far in the future. This attitude explains all kinds of funny survey results. For example, when asked in 2009 what "being old" means, the most popular response among Americans was, "turning eighty-five." In other words, the average American (who lives to seventy-nine) dies six years before entering old age. Here is the reality: in practically every high-skill profession, decline sets in sometime between one''s late thirties and early fifties. Sorry, I know that stings. And it gets worse: the more accomplished one is at the peak of one''s career, the more pronounced decline seems once it has set in.

Obviously, you aren''t just going to take my word for this, so let''s take a look at the evidence. We''ll start with the most obvious, and earliest, decline: athletes. Those playing sports requiring explosive power or sprinting see peak performance from twenty to twenty-seven years of age, while those playing endurance sports peak a bit later-but still as young adults. No surprise there-no one expects a serious athlete to remain competitive until age sixty, and most of the athletes I talked to for this book (there aren''t any surveys asking when people expect to experience their physical decline, so I started doing so informally) figured they would have to find a new line of work by the time they were thirty. They don''t love this reality, but they generally face it. It''s a much different story for what we now call "knowledge workers"-most people reading this book, I would guess. Among people in professions requiring ideas and intellect rather than athletic skill and significant physical strength, almost no one admits expecting decline before their seventies; some later than that. Unlike athletes, however, they are not facing reality.

Take scientists. Benjamin Jones, a professor of strategy and entrepreneurship at the Kellogg School of Management at Northwestern University, has spent years studying when people are most likely to make prizewinning scientific discoveries and key inventions. Looking at major inventors and Nobel winners going back more than a century, Jones finds that the most common age for great discovery is one''s late thirties. He shows that the likelihood of a major discovery increases steadily through one''s twenties and thirties and then declines dramatically through one''s forties, fifties, and sixties. There are outliers, of course. But the probability of producing a major innovation at age seventy is approximately equal to what it was at age twenty-about zero. That fact no doubt inspired Paul Dirac, the Nobel Prize-winning physicist, to pen a little melancholy verse about how age is every physicist''s curse. It ends with these two lines: He is better dead than living still when once he is past his thirtieth year.

Dirac won the prize when he was thirty-one years old, for work he had done in his midtwenties. By his thirtieth birthday, he had developed a general theory of the quantum field, the area in which he had earned his PhD at Cambridge (at age twenty-four). At twenty-eight he wrote The Principles of Quantum Mechanics, a textbook still in use today. At thirty he was a chaired professor at Cambridge. And after that? He was an active scholar and made a few breakthroughs. But it was nothing like the early years. Hence his poem. Of course, Nobel winners might be different than ordinary scientists.

Jones, with a coauthor, dug deeper into the data on researchers in physics, chemistry, and medicine who had highly cited work, as well as patents and various prizes. They found that peak performance is occurring at later ages than in the past, principally because the knowledge required to do cutting-edge work has increased so much over the decades. Still, since 1985, the peak age is not old: for physicists, fifty; for chemistry, forty-six; and for medicine, forty-five. After that, innovation drops precipitously. Other knowledge fields follow the same basic pattern. For writers, decline sets in between about forty and fifty-five. Financial professionals reach peak performance between the ages of thirty-six and forty. Or take doctors: they appear to peak in their thirties, with steep drop-offs in skill as the years pass.

It''s sort of reassuring to have a doctor who reminds people my age of Marcus Welby, MD. However, one recent Canadian study looked at 80 percent of the country''s anesthesiologists and patient litigation against them over a ten-year period. The researchers found that physicians over sixty-five are 50 percent more likely than younger doctors (under fifty-one) at being found at fault for malpractice. Entrepreneurs are an interesting case when it comes to peak age. Tech founders often earn vast fame and fortune in their twenties but many are in creative decline by age thirty. The Harvard Business Review has reported that founders of enterprises backed with $1 billion or more in venture capital tend to cluster in the twenty to thirty-four age range. The number of founders older than this, they discovered, is low. Other scholars dispute this finding, clai.