Parenting expert Dorothy Law Nolte enjoys a huge following worldwide; her 1998 book, "Children Learn What They Live," sold over 700,000 copies in her native U.S. and has been translated into 36 languages. The Japanese version was a steady seller -- until February this year, when the father of a certain 3-year-old girl brought it to public notice and sent sales through the roof.

The girl was Princess Aiko, and the father, Crown Price Naruhito, who, at a rare news conference, read out the poem that Nolte penned some 51 years ago and which served as the inspiration for her best seller. Suddenly, "Children Learn What They Live" became required reading for Japanese parents, and PHP Institute Inc., which publishes the Japanese version of the book, says it has sold 2.25 million copies, 780,000 since late February.

So what is so special about Nolte's message that the Crown Prince felt compelled to share it with the nation? The poem he read out was first published in 1954 in a newspaper in Torrence, California, where she wrote a weekly parenting column. The 19-verse poem, which starts with "If children live with criticism, they learn to condemn," goes on to connect children's aggression with an atmosphere of hostility at home, their sense of respect with the kindness they are shown, and so on. The book elaborates on how to instill each of the values listed in the poem, citing a number of real-life situations parents face -- such as kids crying out "I'm hungry!" while they are preparing a meal -- and creative ways to deal with them.