[3] After fleeing Nazi Germany less than a week after Hitler came to power, Arnold was educated in the UK at Bedales School.
[citation needed] Arnold followed his eldest sister to the United States where he gained work as a writer and cartoonist.
Badly wounded after his jeep ran over a German landmine, he returned to New York where he settled down to married life with Eve.
The success of the book, How To Play With Your Child, which sold over 100,000 initial copies, established Arnold as an author, and allowed the family to buy a house in Long Island Sound.
Arnold had by this time established himself as a national columnist with the Chicago Tribune with a weekly column on childrearing called "Parents and Their Children.