A growing chorus of education researchers, pundits and “science of reading” advocates are calling for young children to be taught more about the world around them. It’s an indirect way of teaching reading comprehension. The theory is that what we grasp from what we read depends on whether we can hook it to concepts and topics that we already know. Natalie Wexler’s 2019 best-selling book, The Knowledge Gap, championed knowledge-building curricula and more schools around the country, from Baltimore to Michigan to Colorado, are adopting these content-filled lesson plans to teach geography, astronomy and even art history.