When I was a boy, I moved to a newly built housing project. The nearby elementary school was too small to accommodate the slew of new kids, but a few miles away, too far to walk to, stood the underutilized PS 119. So, a dozen or so of us 5th-graders took public transportation to the school in Glendale—not a little yellow bus but a lumbering public bus on Myrtle Avenue. No parent walked a child to the bus stop two blocks away; no one drove a child to school. No adult rode the bus with their child. No one thought twice about 11-year-olds walking blocks away to board a bus on their own.

Two years later, I commuted an hour each way taking two subway lines to a high school in Manhattan. I left soon after dawn and, because I was on a varsity team, often returned in the dark. If my mother, who was a worrier by nature, had qualms about my unsupervised travel, she never expressed it. My father would have thought it absurd that I couldn’t manage this on my own. As far as I knew, the parents of all my school acquaintances thought the same.

Helicopter parents emerged in a later generation, fearful of letting their children ride public conveyances alone, afraid of letting them play outdoors without a hovering adult presence, instilling messages about stranger-danger and the menace of unwashed hands.

Now a study posits that keeping children on a short leash, as practiced during the past couple of decades, is one of the causes of the spike in teen anxiety and depression. There are multiple causes for this distressing trend, for sure. The study is small, and there is always the problem of sorting correlation from cause and effect. But this study is suggestive and, despite its limitations, seems right to me.

I remember my parents coming to my defense one time, when they complained to the school principal that I had been hit hard by a teacher with her knitting needles. Today parents act like aggressive public defenders of their children’s right to be free of struggle, failure, or slights. There are times for parents to speak up—when, for example, schools don’t stop bullying or when teachers are abusive. But, on balance, learning how to deal on their own with difficult situations is a benefit that children will reap in adulthood. Intervening on behalf of one’s child is good when done in small doses. Not every slight is a calamity.

Throughout the world, in every culture, a primary role of parents is to ensure the health and safety of their children. But an equally important function is to see that they are prepared for life as an adult. The current attitude of many American parents has veered too far toward the first and too little toward the second. The place where parents need to be is somewhere in the middle, where children are free to be children and parents keep a watchful but distant eye.