Adolescence doesn’t end until you’re 28?!
How the media got it wrong

© 2010 Gwen Dewar, Ph.D., all rights reserved

As I've noted elsewhere, false or misleading stories about scientific research are pretty common. There are several reasons for this. In some cases, the problem is that writers fail to read the studies that they are reporting on. In other cases, writers have dutifully read the original research, but lack the training to understand it.

Then there is an even more fundamental problem: Sometimes, writers repeat claims about research without even checking to see if the research exists. For example, consider a story circulating in the popular media in 2010.

One version, published by, begins with a headline suggesting that a surprising new study has been published ("Study: Adolescence Doesn't End Until Age 28"). Then it proceeds with a warning from a psychologist. If parents are "wondering how long their children will act like teenagers," they "can expect it to last up to the age of 28..."

That's quite a dramatic claim, and one that sounds dubious to many people. Where is the evidence?

As it turns out, the story doesn't provide details about a new study. On the contrary, the only reference to research comes in a single sentence, apparently derived from a comment by Darryl Cross, a clinical psychologist based in Australia whose website describes him as a "leadership and careers coach." The sentence seems to allude to research conducted by someone other than Dr. Cross himself:

"Dr. Cross said U.K. research found in many cases adolescence started at the younger age of eight and extended to 28, instead of the previously believed age range of 12 to 21."

What is this research, and what does this statement mean by the term "adolescence"? Is it meant to refer to a hormonal state? A condition of psychological immaturity? Economic dependence? A heightened tendency to engage in crime? No such information is provided, and I can find no studies where researchers have made the claim that "adolescence doesn't end until age 28."

Misleading headlines and poor fact-checking undermine public confidence 

Does any of this matter? I think so. If the story had attempted to address any of these questions, it would have seemed much less provocative.

For instance, perhaps the statement about "U.K. research" was intended as a reference to brain development. It's well-established that the brain continues to grow and change after the teen years (Sowell et al 2003). But scientists haven't yet shown that brain development after age 21 causes people to behave in ways that are more or less mature. The connection between adult brain development and cognitive maturation is still being pieced together (Luna et al 2004). 

Alternatively, the statement might refer to the fact that adults display less aggression as they get older (Birditt and Fingerman 2005). Or maybe Dr. Cross simply meant that there are different cultural markers of the transition to adulthood, and that some criteria--like financial independence--aren't being met by many young adults today (Arnett 2001).

But as it stands, the story leaves the impression that researchers are proposing something rather outlandish -- that we should expect people to "act like teenagers" until their late twenties. And that, I think, undermines public confidence in the work that responsible researchers do. It makes anti-intellectuals roll their eyes and complain that--yet again--investigators are wasting money and time on ridiculous projects.

Not every study is well-designed or well-executed. But there are plenty of developmental psychologists who do sober, useful, rigorous--and even groundbreaking--work. So to everyone engaged in popularizing research, let's take care. If we are going to refer to research, we need to cite our sources. We need to question the evidence, present the reasoning behind a given claim, and note a study's limitations. And to everyone who reads popular accounts of research, let's demand high standards from our sources of news.

More reading

For another discussion of responsible research and our folk ideas about adolescence, see my blog post "Are you expecting a disrespectful teen?"

Copyright © 2006-2021 by Gwen Dewar, Ph.D.; all rights reserved.
For educational purposes only. If you suspect you have a medical problem, please see a physician.


Arnett JJ. 2001. Conceptions of the transition to adulthood: Perspectives from adolescence through middle life. Journal of Adult Development 8(2): 133-143.

Birditt KS and Fingerman KL. 2005. Do we get better at picking our battles? Age group differences in descriptions of behavioral reactions to interpersonal tensions. J Gerontol B Psychol Sci Soc Sci. 60(3):P121-8.

Luna B, Garver KE, Urban TA, Lazar NA, and Sweeney JA. 2004. Maturation of cognitive processes from late childhood to adulthood. Child Dev. 75(5):1357-72.

Sowell ER, Peterson BS, Thompson PM, Welcome SE, Henkenius AL, and Toga AW. 2003. Mapping cortical change across the human life span.Nat Neurosci. 6(3):309-15.