No War Allowed Until You're at Least 25 - OZY | A Modern Media Company

No War Allowed Until You're at Least 25

No War Allowed Until You're at Least 25

By Sean Braswell

Young people with immature brains are more vulnerable to the impact of trauma, which can trigger a psychotic break in those with a biological predisposition to schizophrenia, bipolar disorder or other mental illnesses.
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Because being young isn’t all it’s cracked up to be, especially on the battlefield.

By Sean Braswell

Welcome to The Thread, OZY’s chart-topping weekly podcast. In Season 4, The Thread explores the controversial criminal defense that ties together some of the most notorious crimes in history: not guilty by reason of insanity. Subscribe now to follow The Thread on OZY.comSpotifyAppleHimalaya or wherever you prefer to stream your audio.

It is the best of times. And, for many, the worst of times too. The college years are an exciting, intellectually stimulating and formative period for lots of young people. But for many, it is also their first experience of severe anxiety, depression or even a major psychiatric disorder. Sometimes a stressful event like a poor exam performance or a relationship breakup can send even those with no history of depression or mental health issues spiraling downward. 

It can be an incredibly fraught and vulnerable time in life, and one of the reasons for that is neurological. As research suggests, a number of latent psychiatric disorders first manifest themselves in the late teens and early 20s, and they can be triggered and greatly exacerbated by external stressors like academic and relationship setbacks. Or, even more acutely — for those who choose to enter the barracks instead of the dorms at age 18 — by the trauma of war. And one obvious policy solution to this physiological reality is clear: Young people should not be allowed to fill combat roles in the military until they are at least 25 years old.

It looks like the rental car companies had it right all along …

Some of the biological underpinnings of severe mental illness are the subject of episode six of Season 4 of The Thread podcast, available on, Apple Podcasts and elsewhere. The latest season of The Thread examines how some of history’s most notorious criminal defendants are linked by a common thread: the insanity defense. Major psychiatric disorders, of course, are not limited to murderers and criminals. The predisposition to them exists on a spectrum, and for a number of us, major environmental trauma is all that’s needed to send our brains reeling in a dangerous direction.

The recent history of the armed forces in America is one of wider inclusivity as military personnel of different races, genders, sexual orientations and backgrounds increasingly train and fight together. But there is still no ignoring the core demographic of the U.S. military (and of most armies through much of human history): young people, especially men, ages 18–24. According to 2016 Department of Defense numbers, around 45 percent of active-duty personnel are under age 25, and 85 percent are male. But such a reliance on under-25s carries some big risks.


For all of the public policy debates about the appropriate age to start driving, voting and joining the military, it looks like, yes, the rental car companies had it right all along. While most of these adult responsibilities are granted by the age of 18, the true age of maturity — at least as far as brain maturation goes — appears much closer to the age that most rental car companies deem you fit to sit behind the wheel: 25. Research shows that the prefrontal cortex of the brain — the part that’s involved in impulse control, decision-making, planning and personality development, among other things — does not finish developing until about age 25 … and it tends to happen later among males than females (shocking, I know).

One of the consequences of brain maturation rates, as neuroscientist James Fallon puts it in his book The Psychopath Inside, is that “a freshman and a senior in college are very different human beings.” And in those formative years between, young people with immature brains are more vulnerable to the impact of trauma, which can trigger a psychotic break in those with a biological predisposition to schizophrenia, bipolar disorder or other mental illnesses. “You have to have the genetics,” says Fallon, a professor of psychiatry and human behavior at the University of California, Irvine. “Then you have to have the trauma. That’s the nature-nurture interaction that changes the circuitry in the brain.”

Which is why Fallon says that sending kids off to war at age 18 is “ridiculous” since their brains are still actively developing. In fact, one recent study found that soldiers who enlisted before the age of 25 were seven times more likely to develop post-traumatic stress disorder. But is it necessary to ban under-25s from combat roles? Wouldn’t this blow a hole in the demographic upon which most militaries depend? 

Not necessarily. The way that the nature of warfare has evolved in the past century makes armies less dependent on young male warriors. Modern militaries need drone pilots, computer programmers, linguists, technicians and other skilled positions as much as physically strong fighters. Plus, it is in the interest of the armed forces to send the people into battle who are best capable of handling it — otherwise, they are a liability to their colleagues and require years of therapy and more to treat PTSD and other conditions.

So, what do you think? Is it time to take a page out of the rental car playbook and raise the age of combat readiness in the armed forces?

Please share your comments below.

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