Levels of perception
as they develop in infants

The Wonder Weeks:
Eight predictable leaps in your
baby’s mental development

Hetty Vanderijt and her husband Frans Plooij have studied the mental development of infants from birth and explain their observations in terms of PCT. Their original Dutch book (1992), listed below, was based on studies of mothers and infants in The Netherlands. This study has been replicated in Britain, Spain and Sweden with consistent results as reported in Heimann, M. (2003). Regression periods in human infancy. Mahwah, NJ: Erlbaum.

American and British: (2008)	The Wonder Weeks: Eight predictable, age-linked leaps in your baby’s mental development   Published Feb 2008 by Kiddy World Promotions B.V. (The Netherlands), and made available through Amazon and other Internet bookstores, this book can be previewed with excerpts from each chapter right here.
Dutch: (1992)	Oei, ik groei! Utrecht/Antwerpen: Kosmos-Z&K.
Dutch: (2004)	Oei, ik groei! Utrecht/Antwerpen: Kosmos-Z&K (Nieuwe versie uitgebreid met twee nieuwe hoofdstukken). (New version with two new major sections added).
Dutch:	Web site       http://www.oeiikgroei.nl/
German: (1994)	Oje, ich wachse! Achtmal steht Ihr Baby kopf München, Mosaik Verlag. (Also as paperback by Goldmann in Munich)
German: (2005)	Oje, ich wachse! München, Mosaik Verlag. (New version with two new major sections added).
Spanish: (2004)	Les semanas mágicas. Barcelona: Ediciones Medici
French: (1997)	Pourquoi pleurent-ils? Comprendre le développement de l'enfant, de la naissance à 1 an Paris, Albin Michel.
Swedish: (1999)	Växa och upptäcka världen. Sju utvecklingssprång under barnets första levnadsår Stockholm, Wahlström & Widstrand.
Danish: (2003)	60 Vidunderlige uger. Otte skridt i dit barns mentale udvikling. Copenhagen: Forlaget Human.
Italian: (2000)	Ehi, sto crescendo. Lo sviluppo mentale del bambino nel primo anno di vita Milano, RCS Libri S.p.A.
Japanese: (2004)	The wonder weeks (in Japanese). Tokyo: PHP.
Korean: (2006)	The wonder weeks (in Korean). (The new version with two new major sections added). Seoul: Daehan Printing & Publishing.
Russian: (2008)	The wonder weeks (in Russian).