“The big picture is that they are taking longer to grow up,” said Dr. Twenge, whose latest book is “iGen: Why Today’s Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy — and Completely Unprepared for Adulthood.”

In an article in The Atlantic last fall titled “Have Smartphones Destroyed a Generation?,” Dr. Twenge argued that teens are more comfortable in their bedrooms or on smartphones or social media than at a party. While they are physically safer than past generations as a result, rates of teen depression and suicide are on the rise. “It’s not an exaggeration to describe iGen as being on the brink of the worst mental-health crisis in decades,” she wrote. “Much of this deterioration can be traced to their phones.”

But a number of social scientists and adolescent health researchers disagree with that conclusion. While teen depression and suicide rates are worrisome, there is no causal link to show those trends are the result of smartphones and social media. In fact, a literature review by Unicef researchers in December found that moderate use of digital technology tends to be beneficial for children’s mental well-being, while no use or too much use is associated with a “small negative impact.” The larger issues that affect a child’s well-being are family functioning, social dynamics at school and socio-economic conditions, the report concluded.

Don Tapscott, author of “Grown Up Digital,” said he believes today’s teenagers are better communicators than any previous generation. “They didn’t grow up being the passive recipients of somebody else’s broadcast,” he said. “They grew up being interactors and communicators. In the 1960s we had a generation gap. What we have today is a generation lap — they are lapping their parents on the digital track.”

The clinical psychologist Wendy Mogel interviewed groups of middle school and high school students around the country in 2015 and 2016 for her new book, “Voice Lessons for Parents: What to Say, How to Say It and When to Listen.” Dr. Mogel spoke with diverse kids from various regions and walks of life, but found herself consistently impressed by their thoughtfulness, how much they liked their parents, and how much they cared about the world around them.

“The press and general public like to see them as spoiled and not having to work hard for anything except grades and being very entitled,” Dr. Mogel said. “But they’re courageous, energetic, optimistic and really smart.”

Neil Howe, a historian whose books include “Millennials Rising,” said that unlike earlier generations, today’s teens have accepted the structures of society and have learned to work within those boundaries. “They’re very good at using rules to make their point, and they’re absolutely excellent at negotiating with their parents, and negotiating in a reasonable way about how to bend these rules in a way that will make them more effective and give them more space,” he said. “This is not a ‘throw the brick through the window and burn stuff down’ group of kids at all. They’re working very constructively, arm-in-arm with older people they trust, to make big institutions work better and make them stronger and more effective.”