At the beginning of 1938 the New York publisher Modern Age Books released Erika Mann's first book in exile, the documentary report, School for Barbarians. The book was a study of methods of upbringing and education under the Nazis. With 40,000 copies sold, the book became a bestseller in the United States. The first German-language edition was released for a European readership by the Amsterdam publisher Querido in the same year under the title, Zehn Millionen Kinder.

On her lecture tours Erika Mann had often spoken about women and children in Nazi Germany and education under the dictatorship, focussing on the impact of pervasive state control on families. The material for the book, which Erika Mann had worked on since the summer of 1937, came from interviews conducted with refugees in Switzerland, newspaper articles, original documents and textbooks as well as from Hitler's Mein Kampf, whose principles on upbringing and education are quoted extensively in the book.

While exposing Nazi educational policies to ridicule through the juxtaposition of contradictory pronouncements, Erika Mann's narrative commentary keeps the otherwise dry documentary material alive, producing the first scrupulously researched investigation into education and language in Nazi Germany. In the preface Thomas Mann paid tribute to his daughter's attention to detail and her stylistic approach.