Malte Mueller/fStop/Getty Images Imagine it’s the 1980s or early ’90s, and there’s a queue for the pay phone in a college dorm hallway. Students line up, waiting their turn for the once-a-week, brief check-in with a parent. That was the norm, says Laurence Steinberg, a professor of psychology and neuroscience at Temple University. “Parents and their adult children are much closer emotionally these days than they had been in past generations,” Steinberg says. The shift, from what he observes as a professor, is dramatic. “To the point where sometimes during midterms or finals, the students have to kind of block their parents from texting them because they’re interrupting them too much,” he says. More than half of parents of 18- to 25-year-olds say they track their adult children using smartphone apps, according to a new University of Michigan survey. And as technology becomes ever more present, and the boundaries between independence and reliance in late adolescence and early adulthood continue to evolve and shift, researchers say tracking can be both a way to stay in …