Tech companies worked hard to get public schools to buy into programs that required schools to have one laptop per student, arguing that it would better prepare children for their screen-based future. But this idea isn’t how the people who actually build the screen-based future raise their own children.

In Silicon Valley, time on screens is increasingly seen as unhealthy. Here, the popular elementary school is the local Waldorf School, which promises a back-to-nature, nearly screen-free education.

So as wealthy kids are growing up with less screen time, poor kids are growing up with more. How comfortable someone is with human engagement could become a new class marker.

Human contact is, of course, not exactly like organic food or a Birkin bag. But with screen time, there has been a concerted effort on the part of Silicon Valley behemoths to confuse the public. The poor and the middle class are told that screens are good and important for them and their children. There are fleets of psychologists and neuroscientists on staff at big tech companies working to hook eyes and minds to the screen as fast as possible and for as long as possible.

And so human contact is rare.

“But the holdup is this: Not everyone wants it, unlike other kinds of luxury products,” said Sherry Turkle, professor of the social studies of science and technology at the Massachusetts Institute of Technology.

“They flee to what they know, to screens,” Ms. Turkle said. “It’s like fleeing to fast food.”

Just as skipping fast food is harder when it’s the only restaurant offering in town, separating from screens is harder for the poor and middle class. Even if someone is determined to be offline, that is often not possible.

Coach seat backs have screen ads autoplaying. Public school parents might not want their kids learning on screens, but that is not an option when many classes are now built on one-to-one laptop programs . There is a small movement to pass a “right to disconnect” bill, which would allow workers to turn their phones off, but for now a worker can be punished for going offline and not being available.