Writers, the good ones, are a short-lived species, and it’s remarkable how few manage to enjoy a happy and productive old age.

Some are cut down in their 20s and 30s before they can achieve their full potential: Keats and Shelley, Katherine Mansfield, Stephen Crane, Sylvia Plath, Emily Bronte, Dylan Thomas, Flannery O’Connor, the brilliant Ross Lockridge Jr., Nathaniel West.

Many are lost in their 40s, in what should have been their writing prime: D. H. Lawrence, Jane Austen, Jack London, Camus, Gogol, Maupassant, Poe, Kafka, Kerouac, Anne Sexton, Antoine de Saint-Exupery, Jack London, Ring Lardner.

A large number don’t make it out of their 50s or early 60s, young by today’s standards, when they’re still capable of important work: Dickens, Flaubert, Emily Dickinson, Balzac, Dostoyevsky, Proust, Richard Wright, Virginia Woolf, Hemingway, Faulkner.

Surprisingly few make it to their 70s, and those who do often outlive their reputations. John Updike, like John Dos Passos before him, kept publishing novels right until his death, but readers and reviewers had long since stopped paying anything more than polite attention.

A small number survive into their 90s, though for the most part no longer writing or publishing: Eudora Welty, Harper Lee, E.M. Forster, Rebecca West, Katherine Anne Porter, Solzhenitsyn, Salinger, and, patriarch of them all, George Bernard Shaw, who died at 94 from complications attendant upon his falling out of an apple tree.

In terms of longevity, writers are about on par with NFL linemen, and you can only speculate as to why. Poverty, solitude, neglect, a bookish life spent indoors, the wounds inflicted by publishers and critics. These take their toll. Suicide, depression and alcoholism have played their part, and hardly anything cut off more talent than tuberculosis, which did in three of my heroes: Thoreau (44), Chekhov (44) and George Orwell (46).

And there’s another kind of mortality writers have to worry about: death of their talent, loss of creativity, sclerosis of the imagination. Orwell, perhaps sensing his own early death and trying to find solace, addressed the issue head-on.

“A novelist does not, any more than a boxer or ballet dancer, last forever. He has an initial impulse good for three or four books, perhaps even for a dozen, but which must exhaust itself sooner or later…. The creative impulse seems to last for about fifteen years, probably between the ages of 30 and 45…. Most writers ought simply to stop writing when they reach middle age.”

Ouch. He does hold out some hope: “A few writers have a much longer lease on life, and can go on developing when they are middle-aged or even old.”

But scan the work of important writers over 70 and it’s startling how few still kept creating at a high standard right to the end. Tolstoy wrote his last great novel, Resurrection, when he was in his 70s, and when Melville died he was working on the manuscript of Billy Budd, but if there are other prose masterpieces written when their authors were over the age of 75, I can’t think of them. (Readers who can, drop me a line and I’ll stand corrected.)

Orwell is right — much of this can be attributed to the decline in energy and stamina almost everyone experiences as they age — but an especially precipitous decline seems endemic to writers. Scientists who specialize in “evolutionary psychology” have even studied this; they’ve noticed that male writers (as well as male physicists, composers, even criminals) seem to reach their peak in their mid-30s, then experience an increasingly rapid decline in their abilities and outputs.

Dr. Satoshi Kanazawa believes she has an explanation. “Young men in any profession are driven to seek wealth and prestige because these attributes are attractive to women. Once men’s urge to start a family has been satisfied, the wellsprings of productivity, whether in science, art, or crime, run dry.”

Dr. David Buss concurs. “Artistic endeavors are driven by men’s pursuit of wealth and status. The peacock’s tail is a flamboyant encumbrance of no help at all for physical survival, but of great value in seducing pea hens.”

Hmm. Maybe. But wealth and prestige, now as ever, are in short supply for serious writers, and the decline in writing ability seems to affect older women just as it does aging men. Orwell’s explanation seems simpler and more accurate. You have a certain number of books in you, you write them, and then, if you continue writing for love or money, you’re either repeating yourself or running out of gas.

More and more writers seem to accept this and officially announce their retirements. Vonnegut did this, then promptly “un-retired,” while Phillip Roth has so far stuck to his resolution. “To tell you the truth,” he told an interviewer when he reached 79, “I’m done.”

Some old-timers soldier on. Saul Bellow published several novellas when he was an octogenarian, and while they were respectfully received, it was the kind of reaction you would get watching people that age play tennis — it’s not very good tennis, but what a miracle they can play at all!

But does it have to be this way? Artists in other fields stay productive well into old age. Picasso was painting in his 90s, and Verdi, who died at 87, wrote operatic masterpieces right to the end. And here in the 21st century we’re learning to change our expectations about what elderly people can achieve; if 60 is the new 40, why can’t senior writers turn out novels and stories as powerful and original as those they wrote in their 20s?

Physically the work isn’t onerous; writing keeps the brain sharper than doing Sudoku; a lifetime’s experience is there to be tapped. Sure, your cultural mindset might be stuck in the decades of your youth, but that can eventually be a good thing, bringing a different, valuable perspective to today’s shallow world. Live long enough and the old-fashioned becomes the avant-garde.

Approaching old age myself now, at least for a writer, I find myself remembering Herman Melville, whose last years are simultaneously the saddest story in American literature and the most inspiring.

Moby Dick almost universally scorned, his subsequent writings ignored by publishers and critics, considered by those close to him as insane, remembered only as “the man who lived with cannibals” back in the l840s, he wrote on, mostly poetry now, not novels, showing his work to no one, living a life of total artistic solitude, so, when he died in New York City in 1891, what few obituaries appeared expressed surprise, not that he had died, but that he had still been living.

His grieving family found two things when they finally got the nerve to break into his sacrosanct study. On his desk, the uncompleted draft of Billy Budd. On the wall, a printed quotation from Schiller: Stay true to the dreams of thy youth.

W.D. Wetherell is a novelist, story writer and essayist who lives in Lyme.