Every children's book says four to eight. It is the safest range in publishing (nobody has ever been sued for saying four to eight), and it tells you almost nothing.
So let me be more useful than that.
At four, they are listening to the sound
A four-year-old is not following the moral. They are following the rhyme, and they are waiting for the animal. That is enough. A fable at four is a song that happens to have a story in it, and the child who cannot yet tell you what boastfulness means will absolutely tell you that the swan was showing off.
Read it for the noise. Do the voices badly. The lesson will still be sitting there in three years when they are ready for it.
At five and six, the penny drops
This is the middle of the range and the best age for the book. Five and six is when a child starts noticing that the story is about somebody they know (usually a sibling, occasionally you). They begin predicting the ending. They argue with it. One of mine used to insist the fox was right, which is a much better sign than agreement.
This is also the age where the fault having a name starts to matter. On the first page of every fable the word is printed in gold. Impatience. Rudeness. Vanity. A child who has a word for a thing can talk about the thing, and a child who can talk about it is halfway to noticing it in themselves.
At seven and eight, they read it to you
Now the rhyme stops being decoration and starts being a scaffold. A child who is reading aloud and gets stuck on a word can often guess it from the rhythm, which is exactly the moment reading turns from work into reading.
Seven and eight is also when the card deck takes over. Twenty-six fables is a lot of story, but fifty-four cards is a game, and a game survives being played on the floor for a year.
Where it stops working
Nine and above, honestly, is pushing it. A nine-year-old will enjoy the paintings and will be too old for the moral being stated out loud. I would rather tell you that than sell you a book your child grows out of in a fortnight.
Under three is too early, though I have been told by more than one parent that a two-year-old will sit through the songs quite happily. Two-year-olds will sit through anything with a tune. That is not the same as the book being for them.
The mixed-ages problem
If you have a four-year-old and a seven-year-old, this is the rare case where one thing does both, and it is the reason the ecosystem exists at all. The younger one gets the song and the picture. The older one gets the fable and the game. Same animal, same evening, different depth. (Which is also, I admit, the only way I have ever seen two children agree on anything.)
So, plainly
Buy it for a five or six-year-old and you have got it exactly right. Buy it for a four-year-old and you have got two good years ahead. Buy it for an eight-year-old and read it fast, because the window is closing.
The full ecosystem is twenty-six fables, twenty-six songs and karaoke videos, the card deck, the online games and the colouring book, $49.95 during the launch, shipping from 12 September.
And if you want to test the water before spending anything, the twenty-six colouring posters are free. Print them, watch which ones come back covered in felt tip, and you will know your child's age better than any range on a back cover.
Tomorrow I will open the box and show you every piece of it, including the parts that are not in the box.