As a population, it’s exotic to the point of extinction, vanishing in plain sight: the American adult.

As a trend, this has been gestating for at least the past decade, from Judd Apatow’s glorified man-babies to Lena Dunham’s ostensibly grown “Girls” to the acceptance of “adulting” into the lexicon. But it truly, alarmingly calcified this summer.

Take prime-time TV. This summer was awash in game shows, major stars — including Justin Timberlake, Jimmy Kimmel, Rob Lowe, Ellen DeGeneres, Alec Baldwin, Tiffany Haddish, Elizabeth Banks, Duane “The Rock” Johnson, Melissa McCarthy (recent Oscar nominee) and Jamie Foxx (Oscar winner) — producing and/or emceeing.

“What it comes down to is that the movie business has changed,” Baldwin told Vulture in June. “They’re going to put up a lot of money, including big fees for ‘Iron Man’ and those kind of tentpole films. [But] everything else, the fees in the movie business have collapsed.”

To Baldwin’s point, just look at the five top-grossing films this summer: “The Lion King,” “Toy Story 4,” “Spiderman: Far From Home,” “Aladdin,” and “John Wick 3.” The biggest album release of the summer, if not the year, came awash in pastel colors, animation, dollhouses and heart-shaped glitter-bombs: The ostensibly adult-themed “Lover” by Taylor Swift, age 29.

A recent front-page story in The Wall Street Journal reported on recess for grownups, a new industry in which otherwise high-functioning adults pay good money to play dodge ball, kickball, hopscotch and gorge on grilled cheese and chicken nuggets. Quieter play with Lincoln Logs, Play-Doh or Silly Putty is also encouraged.

And for those who prefer more traditional summer escapes — taking, say, a cruise — Carnival Cruises, headquartered in Florida, announced the first cruise ship to have a roller coaster on deck. And for any guest averse to riding 187 feet above sea level at 40 miles per hour, they can play “Family Feud Live” on a recreated set.

It all comes full circle. But when it’s no longer enough entertainment to be headed for foreign locales, distracted by casinos and discos or restaurants or, say, the majesty of the open sea, we have hit a cultural and societal nadir.

There are multiple factors contributing to the death of adulthood, including the last recession, which has retarded the economic and social progress of millennials. As a cohort, they are living with their parents longer, carrying more debt than the previous generation, and delaying marriage and home-buying. Behind them is Gen Z, which, according to the American Psychological Association, reports the highest levels of stress than any other generation.

Gen Z’s salve and stressor? Social media, which they say can be a support (55%) or an anxiety-inducing black hole (45%).

This, it seems, is ground zero for this phenomenon: technology. Email pings and text alerts and “likes” are turning us into little more than Pavlovian reactors. A study out of London this week finds the average person frustrated if it takes more than 16 seconds to load a webpage or 25 seconds for a traffic light to change.

We are losing crucial emotional and mental capacities for self-reflection, for wandering thought, for the ability to tolerate boredom. And that is the very definition of being a child — all id, out of control, demanding and needy and dependent. It’s poisoned our politics and our personhood, the terrible irony is this: Only we can fix it.