Fifty is the perfect age to write a novel, a study of the best-selling authors of the past 50 years has shown.
Stephen King, 57, is one of the best-selling authors in the US
The average age of writers who topped the hardback fiction section of the New York Times Bestseller List from 1955-2004 was 50.5 years.
"We wanted to discover the optimum age to write a best-seller," said Bob Young of Lulu, a website for writers and independent publishers.
"Unlike scientists or musicians, say, writers tend to mature with age."
Romantic novelist Judith Krantz and writer Joe Klein, who published political comedy Primary Colors anonymously, are among the novelists who topped the best-seller list in their 50th year.
Of the 350 authors who saw their novels reach the number one spot over the past 50 years, Francoise Sagan was the youngest with Bonjour Tristesse, published at the age of 19 in 1955.
By comparison, Agatha Christie was the oldest author to top the list, with her novel Sleeping Murder, published shortly after her death at the age of 85.
The authors who most frequently topped the list were horror writer Stephen King who has topped the list 27 times, and Danielle Steel who has amassed 26 number ones.
Nonetheless, authors like JK Rowling and Da Vinci Code writer Dan Brown, who both achieved global fame in their thirties, appear to be bucking the trend.