Happy Puppy, Angry Tiger is a delightful boardbook that helps toddlers recognize their feelings and build empathy toward others. Each page brings us an animal and what they feel: a bored jaguar, an excited lemur, a frustrated monkey, and so forth.

The educator/artist couple who designed the book, Brad and Betsy Petersen, wanted a way to help their children build a vocabulary of emotions, but they couldn’t anything already on the market that worked the way they wanted. Together they founded Brighter Fun, a children’s social-emotional design group that makes fun and meaningful learning tools like card games, posters, and this book.

Three aspects of the book make it special. One is its varied but always simple and expressive phrasings:

“Watch out for that angry tiger!”

“What a grouchy pig.”

“Sssometimes the sssnake is sssneaky!”

A second appealing feature is the illustrations. They started one day when Betsy was at her desk and drew a really bored cat, because she had seen their kids look at her that exact same way. Her son thought it was funny and said he felt like the cat all the time. So then she started drawing other animals, and we who get to see this book are the beneficiaries.

And third, the puppy may be happy and the tiger angry, but the book also offers sprinkling of emotions you don’t usually see in books for very young children: an anxious alpaca, a grateful praying mantis, a disappointed hedgehog, a disgusted bear, a hopeful meerkat, a reserved koala bear. All in all, you’ll find 24 feelings on these pages, a larger vocabulary of emotions than many adults have.

You can tell that the book was written by parents and educators who tested their ideas with kids. If emotional wisdom — essential to self-esteem, diplomacy, merciful service, and many other arts — starts with knowing what we’re feeling, this little book in its simplicity could have an impact on the world out of proportion to its size.