This is a horribly overused and exaggerated stereotype which simply isn't real. It's real for a small minority which often ends up being considered more or less "bad" or "problematic", and it's partially real(as in one or more descriptor but not all and/or only to some limited extent) for many more, but it's not a universal truth.
I could give you lots of examples, but i'll just say, it's stereotype because it happens repeatedly and when it does it is very noticeable, making it seem more common than it is, not because it's true for all or even most people.
Yeah...given that the prefrontal cortex (which is commonly linked with preventing and controlling the behaviors ensou cited) is generally still developing until the age of 25, it's not an entirely unfounded stereotype. Sure, kids and teens can be and are often mature in specific areas, usually based on their experiences in life. Put a kid through the right experiences, and they'll mature in related areas more rapidly. However, that doesn't mean they're fully mature in all areas, nor that they're ready to be treated as adults in all areas of life.
I say this as someone who definitely had areas in which I was far more mature than my age indicated at pretty much every stage of my life. Still didn't stop me from being hormonally illogical in ways I simply wouldn't be now, back when I was a teenager. I had a pretty massive chip on my shoulder when I was younger. It didn't take much for me to write someone off as not being worth associating with or being nice to, and took not caring about what others (beyond my friends) thought of me to an extreme. Now? I hold doors for just about anyone, because why the hell not make someone else's day little better at the cost of fairly minor inconvenience for myself (which often gives me a little more time to listen to music in the bargain)? I don't necessarily care what strangers think of me, but I don't just write them off as not worth my time for looking at me funny, either.
Teens all have a lot of room to grow and improve, and are going to make mistakes. This is expected. If they exceed those expectations, excellent. If not? Well, they're teens. We cut them a bit of slack, for not having the experience, self-control, or maturity required to always respond to situations correctly.
Admittedly, Panacea's actions exceeds the boundaries our usual allowances for teenage hormones considerably, but there are other complicating factors in her case, including massive physical and mental strain. Given that the strain of the profession her powers forced her into can and does break mentally-balanced, fully-grown adults, I'd say the game was rigged against her long-term sanity from the start. Even if, from where some sit, it looks like a string of terrible actions and behaviors that qualifies as evil.
...I feel like I should work a joke about brain-surgery-by-bullet in here somewhere, just to round out the New Vegas reference, but I don't quite know how...
sigh*
Everything you state above is exaggerated to the point where if it was real, being a teenager would equal being legally insane or at least completely unaccountable for their own actions, ALWAYS, without exception(in reality it is the opposite, fancy that, just reduced liability). By the same logic, female teenagers should be considered adults about 20 days of the month, and then judged as a teen for 5-10 days per month until menopause. While males should be considered adolescents for forever, as we keep having far more hormones fluffing around ever since puberty starts. It also suggests that pre-pubertal children are more adult than teenagers.
And if it is true, why don't you explain why the MAJORITY of people going through adolescence does NOT behave like the stereotypical teenager? I can count on my fingers the number of people i have known in my 44 years that could be considered an "absolute mess of emotions, bad decisions, self-centric worldviews, and craziness" and still have several fingers left because that's the extreme outlier that is very rare.
As i already stated, the stereotype is based on a rather small minority, which gets noticed far more exactly because they stand out from the norm. While the average is to exhibit the stereotypical behaviour to SOME degree or partially in some ways.
Many teens argue with their parents, some rebel more or less, some DO get emotionally messed up, some make bad decisions etc etc.
But extremely few do it all to the point of "absolute mess".
And more importantly, none of those things are limited to teens but mostly to SITUATION, and if you're prone to any of them in your teens, you probably were prone to them BEFORE your teens and still are prone to them AFTER your teens as well.
Being a teenager CAN exaggerate things, but there is absolutely nothing guaranteeing that so happens and it's far more likely to be situational than biological. "Teenager" is NOT a binary thing of yes or no.
Also, changing personality usually has very little to do with "teenager", it tends to happen when something important or drastic happens, regardless if you're 5, 15 or 50 years old.
As someone who was a teenager slightly more recently...I feel you're half-right, and half-wrong, here. I wasn't much of a stereotypical teenager in a lot of ways. I did argue with my parents, but I did that before I was a teen, too. I'd always tried to be independent in my thought processes, even if I wasn't always the best at it. I'd also always liked looking at the big picture, and trying to solve problems. That never changed, even if I've gotten better at it over time.
But, in-retreospect, I was a pretty different person as a teen. Way too tightly wound, way more prone to taking offense, way more judgmental, way more emotionally volatile. Admittedly, some of that change was probably from having to deal with my physical health tanking at 16, forcing me out of school, and forcing me to reduce my stress levels. But some of that was probably my brain developing beyond that mindset.
And shall we bet on you changing those positions ONLY while you were a teen? No? And there's the problem about exaggerating "teenager behaviour". People have a tendency to change more and faster during teenager years because most of the time, there's a lot happening to them then to cause it, but the reason for changing is usually not directly because they are teenagers either in age or development, but because of the situation.
Ah but here's the problem about thinking like that, it's based on the by now extremely obsolete view that the brain becomes more or less immutable later in life. And on the assumption that we don't do that before we become teens. Some do, some don't. Some do it AFTER they're teens. Some NEVER do it.
Your writing is overall excellent and my arguments should in no way be taken as any form of critique against it. The funny thing here is that you already DO portray teens in writing as individuals and NOT as the stereotypical exaggerated teenager you said they must be shown as.
So you've effectively already disproved yourself there.
The brain might never be entirely immutable, but you're just flat out wrong that the idea that the brain isn't fully developed until around 25 is obsolete. Like...it's the current consensus. You can disagree with it all you like. Indeed, I encourage it. That is, after all, how science progresses. But your disagreement doesn't stop the consensus from being the consensus, either.
I fully agree, the brain is develops in response to the "situation"...but the situation is as much biochemical as it is anything else, and puberty has major biochemical and neurochemical consquences. If it didn't, I probably wouldn't have suddenly developed bipolar disorder as a teen, likely due to the genes I have that are linked with the disorder finally coming into play. We aren't shaped purely by nature, sure, but it ain't purely nurture, either. Yes, puberty and brain development isn't one-size fits all. Yes, there are outliers in pretty much every area of development. Yes, the "average human" is a purely statistical construct. So what? Averages and general trends still have utility in predicting general outcomes. So long as you treat them as a baseline only, and adjust your views of a person based on new data, they serve a useful function.
From the sounds of it, I think your issue is less with the general view of teens, and more in how people use it to look down on them, or to justify them making completely random decisions in fiction. Which I'll agree is stupid, and that viewpoint severely grated on my nerves when I was younger. People are people, no matter the age. People are individuals, and need to be treated as such. My parents treated me that way, and it's how I treat my younger brother's teenage friends. But I equally expect them to be a little volatile, emotionally, same as I am when my neurochemistry isn't being corrected by medication. Because they
are just a touch insane, IMO, due to the hormonal storm of puberty. Not always, not even most of them time, and not all of them. But enough that I keep it in mind.
Puberty is significantly worse if you add in actual mental illnesses, too. It tends to exacerbate them significantly, and, typically, teens are still working on figuring out their own coping mechanisms, so it makes everything much more complicated, especially for those not being treated. Honestly, whoever the f*ck decided to throw a teen into one of the most mentally stressful professions in the world without a therapeutic safety net is a damn fool, and I blame them significantly more than I blame Panacea for her breakdown and the results of it. That she was the only person able to save the lives that she did doesn't excuse putting a teen into a profession that is inflicts enough trauma and emotional stress to seriously harm the mental state of most adults, without providing even the most basic of mental health oversight to try and spot the signs of burnout. Even if they thought her powers could only heal, her mental health shouldn't have been neglected like that. A breakdown was pretty much inevitable, IMO.
(Note: I'm not much of a fan of Worm, and have only read the occasional fan-fic for fun. However, two of my aunts work(ed) in the nursing field, and I'm pretty sure the stress of the job, combined with other mental and physical health issues, some due to self-medication, was a factor the early death of one of them. It's an incredibly stressful job, and I can't imagine curing fatal illnesses day-in, day-out is much less so.)