Experts say today’s teenagers are waiting to get a driver’s license, start drinking, and engage in sex. Why are they reluctant to enter adulthood?

Are today’s teens taking longer to grow up than their predecessors?

According to a recent study published in the journal Child Development, American adolescents are waiting longer than past generations to participate in activities associated with adulthood.

Researchers from San Diego State University and Bryn Mawr College analyzed four decades worth of data from seven nationally representative surveys of adolescents in the United States.

They found that in recent years, fewer adolescents are working for pay, driving, going out without their parents, drinking alcohol, dating, and having sex than in previous decades.

Since the early 1990s, for example, the percentage of high school students who work for pay has dropped from 57 percent to 32 percent among 10th graders. It’s dropped from 72 percent to 55 percent among 12th graders.

Over the same time period, the proportion of high school students who drink alcohol has declined by 40 percent among 10th graders and 26 percent among 12th graders.

The share of high school students who’ve had sex has also declined, from 54 percent in 1991 to 41 percent in 2015.

The researchers report that adolescent participation in adult activities has declined across gender, race, ethnicity, socioeconomic, and geographic strata.

They suggest that a “broad-based cultural shift” has taken place, in which a generation of young people is “taking on the responsibilities and pleasures of adulthood” later than before.

Are teenagers less likely to participate in activities associated with adulthood because they’re busier with homework and extracurricular activities?

Not according to this study.

Researchers found that time spent on homework and extracurricular activities has declined among 10th graders. It’s remained relatively steady among 12th graders.

On the other hand, internet usage has increased. This might account for some of the changes.

In fact, one documentary labeled today’s teens as “screenagers.”

The study researchers also found an association between a slower developmental trajectory and smaller family size, higher parental age at first birth, and higher median income.

With fewer children and more money, parents can invest more time and resources in their kids. This may allow them to follow a slower developmental path.

“Greater parental investment leads to teens growing up more slowly because parents supervise children and teens more carefully and organize their activities,” Jean Twenge, PhD, a professor of psychology at San Diego State University and lead author of the study, told Healthline.

“There are also economic factors. With shifts in the economy, more people go to college and are dependent on their parents for longer. That also engenders more careful nurturing with the idea that education will last longer,” she continued.

Other researchers have also highlighted the role of economic and education changes in shifting patterns of adolescent and adult behavior.

For example, Jeffrey Arnett, PhD, research professor of psychology at Clark University in Massachusetts, has found that 18- to 29-years-olds spend more time getting educated, marrying later, and having children later than previous generations.

“There are a lot of things involved, as there is in any big social change, but part of it is the economic change from a manufacturing economy to what’s been called a knowledge economy,” Arnett told Healthline.

“It takes longer to prepare yourself for a place in the economy, and so people stay in education longer. They usually go through a series of short-term jobs in their 20s before they settle into a stable career path, and that partly contributes to making the marriage age later and the age of having your first child later,” he continued.

Arnett suggested that the decline in adult activities among younger adolescents fits into this larger picture of people growing up more slowly and entering adulthood later.

According to Twenge, there are benefits and drawbacks to the decline in adult activities among adolescents.

On the upside, teens are less likely to engage in risky behaviors. They’re more likely to wait until they’re ready to participate in adult activities.

On the downside, they may arrive at college or work without much experience making their own decisions and leading independent lives.

Arnett considers the slower developmental path of today’s teens to be largely positive.

“Things like unprotected sex, alcohol and most other substance use, and crime rates have gone way down among adolescents. Another thing that’s really gone down is rates of automobile accidents, especially in the last 10 years,” he said.

“And I think it’s pretty clear that a lot of that is explained by what Twenge is reporting here. You have fewer kids getting their license right away at 16 or even 17 or 18. They’re not in as much of a hurry to do that because they’re spending more time at home and their parents are more willing to drive them where they want to go,” he explained.

“Now that’s a big thing, to have automobile fatalities go way down, and it’s an example of why we should celebrate this. Giving kids more time to make their way gradually into adulthood is a good thing in many ways,” Arnett noted.