The Wonder Weeks is the English translation of the Dutch book Oei, ik groei! (literal translation: Ai, I'm growing!) by physical anthropologist Hetty van de Rijt and ethologist and developmental psychologist . Originally published in 1992, it has been republished several times, with an updated 6th edition published in 2019. Drawing on many years of observation and analysis of infant development, it gives parents practical guidance to help their baby's cognitive development through its predictable stages or 'leaps'. Its theoretical basis is Perceptual Control Theory, which predicts and explains the observed phenomena. Questioning of the research with mother-infant dyads has received some attention in the press and social media, though sometimes reducing it to a matter of sleep schedules. Th