In the ’70s, the most common family unit in America featured four children, according to a Pew Research Center study from 1976. At that time, only 24% of mothers between the ages of 40 and 44 had birthed just two children. Today, however, the default family size across America has shrunk to two children per unit. The Cut attributes this many things, including the fact that “millennials are waiting longer to get married and women are waiting longer to have children.” The publication also notes that housing and education costs have soared. Author Adam Sternbergh, “middleborn” himself, explores the changing demographics and the role of middle children in society. Read more of Sternbergh’s thoughtful piece at The Cut.