A strange thing happened to mothers and fathers and children at the end of the 20th century. It was called “parenting.” As long as there have been human beings, mothers and fathers and many others have taken special care of children. But the word “parenting” didn’t appear in the U.S. until 1958, according to the Merriam-Webster dictionary, and became common only in the 1970s.

People sometimes use “parenting” just to describe what parents actually do, but more often, especially now, “parenting” means something that parents...