"In 2007, researchers logging questions asked by children aged 14 months to five years found they asked an average of 107 questions an hour. One child was asking three questions a minute at his peak.
But research from Susan Engel (...) finds questioning drops like a stone once children start school."
CHIUDETE. LE. CAZZO. DI. SCUOLE.
https://www.theguardian.com/education/2020/jan/28/schools-killing-curiosity-learn