He is the one we proclaim, admonishing and teaching everyone with all wisdom, so that we may present everyone fully mature in Christ. Colossians 1:28

There has been a long-held belief that chronological age goes hand in hand with maturity. The transition from adolescence to adulthood was measured by birthdays. You became an adolescent as a teenager.

When you reached 21, you were considered an adult for most purposes. Then, at least in the Western world, the age for certain things dropped to 18 (such as voting, signing contracts, etc. ). Most states prohibit someone under 21 from buying alcohol (which is a good thing).

But for most of my life, turning 21 was a rite of passage into adulthood and everyone assumed that it was the real test of maturity.   Well, until recently.

Starting in the 1980’s, researchers found  that the normal chronological benchmarks that had existed for much of the 20th century no longer applied. In fact, some authors saw this early on, such as Gail Sheehy, who wrote a book in the 1980’s and then another one (New Passages) updating it 10 years later to re-test her research.

Her thesis is that the benchmarks we grew up with – being an adult at 21, and middle-aged in your mid-40s – had slid 10 years. Becoming an adult did not match chronological age any more.

Sociologists like Tony Compolo wrote extensively about the impact of over-parenting in Who Switched the Price Tags in 1986.  His conclusion, as a sociologist, was that parents have raised a generation of kids who don’t want to become adults.

Not surprisingly, studies by neuroscientists have found that the human brain doesn’t completely develop until the early 20’s.

Things get even more confused by a recent push in the U.S. to reduce the age for voting from 18 to 16.  Given the research, I would think it would make more sense for the age to go up, not down.

A new study by British scientists confirms that people don’t become adults until their 30’s.  The study by an Oxford professor, Peter Jones,  basically says that the transition from childhood to adult is more nuanced and that the brain generally doesn’t mature completely until at least the age of 30.

Jones notes that the date you arrive as an adult may be “different for everybody.”  He notes that societal definitions of adulthood based purely on age “looks increasingly absurd.”

Millennials, in general, have demonstrated that they are not ready for adulthood until their late 20’s or early 30’s. Many still live with their parents. They haven’t matured to the point that they have checked off several steps that most societies use in determining someone has reached adult status:

  • Completing education
  • Getting a job
  • Leaving a parental home
  • Forming a committed relationship
  • Becoming a parent

Close to 25% of millennials aged 21 to 34 still live with their parents in the U.S. even though the recession is over and jobs are plentiful.  For those in their 20’s, the numbers are even worse with 33% of millennials living with parents. It’s the highest percentage in 75 years.

Based on the above matrix of indicators, it’s a pretty simple test of where a millennial is on the road to adulthood:  Are you still living with your parents?

This is a broad brush-stroke on maturity, but the evidence is fairly strong. I do need to say that I don’t measure all millennials by this.  I know many in their 20’s and early 30’s who have achieved adulthood by any measure, not just years.

One additional component, as Compolo noted, is the over-parenting.  You’ve heard of the “helicopter parent” who hovers constantly over their children.  Now you have a more robust version called either the “lawnmower” or “snowplow” parent, who assiduously plow down any obstacle or possible failure in the path of their children.

In one study,  graduates two years out of college admitted that they didn’t think they were “adults” yet.

There is no reliable way to determine when one is an adult other than the five criteria above. Those may occur at 20, or they may occur at 34.  The latter two – forming a serious relationship and parenting –  are occurring much later (if at all) in the millennial world.

In a future post, I will look at what happens to adolescents when they have all adversity removed from their life. Hint:  it is not a good result.

MENTOR TAKEAWAY:  Your mentee may be old enough to be an adult from the passage of time, but inside may be ill equipped to make adult decisions. You can help them along that path by walking beside them.


Pew Research on young adults living at home.

British Study on Brain Maturity in the 30’s.

An earlier post of mine on Maturity.

Millennials have too many Feelings and Their Parents are to Blame. Newsweek (2018)

Millennials and Having Kids – A Problem for their Parents  Forbes

Millennials Marrying Later  NY Times

WORSHIP:  Listen to Holy Ground by Passion with the lyric: “Jesus Changes Everything”

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