New research says your adolescence doesn’t actually end at age 19

How do you know when you’re a living, breathing, mature adult? Is it when you learn how to grocery shop, buy your own sheets, or get a credit card? Or is it when you graduate from high school or college or cross that time-based threshold of being an age that ends in teen to 20? Well, new research published in The Lancet Child & Adolescent Health found you shouldn’t really consider yourself to be an adult until you’re 25.

The concept of a teenager is a somewhat recent one and has remained unchanged since its inception in the 1940s, even though life expectancy has elongated since then. But, by that vague concept’s guidelines, age 19 is widely accepted as the last year you can still claim to be in adolescence, a term Merriam-Webster defines as “the period of life when a child develops into an adult.”

“Arguably, the transition period from childhood to adulthood now occupies a greater portion of the life course than ever before at a time when unprecedented social forces, including marketing and digital media, are affecting health and wellbeing across these years.” —The research team

As the research points out, the traditional markers used to determine adulthood—finishing education, getting married, having kids, buying a home—are all things that millennials have notoriously either bucked entirely or postponed longer than previous generations.

But why is this happening? “Arguably, the transition period from childhood to adulthood now occupies a greater portion of the life course than ever before at a time when unprecedented social forces, including marketing and digital media, are affecting health and wellbeing across these years,” the researchers wrote in the summary of findings.

By examining a number of biological markers, including average age of puberty, and social indicators, such as the age that people are moving out of their parents’ home and the amount of time people are taking to complete their education, the researchers concluded that the definition of adolescence should be revised from age 10 to 19 to age 10 to 24.

Certain policies are currently in place to reflect this lifecycle shift, such as the Affordable Care Act (which heroically allows young adults to be dependents on their parents’ health insurance plans until age 26). But extending and growing similar initiatives in other fields could help ease the woes associated with the rough economic situation that the younger generation is set to inherit and the daunting uncertainty about the future, both environmentally and politically. At the very least, it would probably go a long way in helping the youth deal with its super-serious stress problems.

Dealing with stress (the millennial bogeyman)? Here’s how Molly Sims battles stress and how to break the cycle of stressed-out overeating.