Even if it is, this explains the joke at least.

Ah, my apologies then. I don’t agree with the parameters the thread OP defined.

Yeah, but that’s the traditional things that are arbitrary. Those decisions weren’t really made by scientific consensus, but more by societal needs and norms. In older times you were also considered an adult earlier because that benefitted society at the time.

As we learn more, and as society and its issues changes, so do these agreed upon lines. It’s less shameful to continue living at home into older ages because housing markets are harder now, and the brain development thing may not really affect work and the like, but some are arguing that it changes the effect of drugs/alcohol/trauma/life long decisions etc.

Whether this could change how we decide if those ages should affect the items you mention are yet to be seen, but keep in mind stuff like Insurance companies finding people under 25 more risky than above 25. Some industry could argue (probably unsuccessfully) that they may need to move it to 32, or people may start suggesting marriage etc should be later than the 20s, etc.

Nah, I’m mostly saying it isn’t black and white. It will have some effect on all layers, but I agree it wouldn’t stop all violence. To take your note about school shootings; yes, many of them are from legally purchased firearms, often a parent or something. Not all of course, so a gun ban would probably reduce, but not eliminate, school shootings. Plus outright bans aren’t the only form of gun control the US hasn’t tried, there are multiple things that can be done to limit without outright ban guns.

Science does move on. I believe recent studies have pushed the brain development ending date past the previously thought 25 years old.

https://www.bbc.com/news/articles/cgl6klez226o

This study suggests it lasts until 32, where you are generally a steady adult until 65.

We probably need more confirmation from more studies, but that’s one explanation.

Not making a specific argument for or against your argument, but I’d like to object to this like:

Let’s not forget that a gun ban will only affect law abiding citizens.

I’ve seen this argument used a lot, but it’s a broad generalization. You are assuming all criminals are the hardest criminals who will disobey any law, but a lot of law breakers and a lot of gun violence perpetrators are first time offenders, or someone who thinks they can get away with minor things.

A lot of people will do legally ambiguous stuff if there’s a low chance of being caught and punished but wouldn’t put themselves on the line for more heavily enforced things, plus even just the hint of illegality will put a type of social pressure on someone.

Will hardcore criminals still get and use guns? Absolutely. Are all gun deaths perpetrated by hardcore criminals? Absolutely not. Even that annoying brandishing couple at the BLM protests a while back would likely not have had the courage to bring out their weapons were it illegal to do so, since they tended to abuse law and loopholes rather than outright break them. They’re a milder case, but the point works with others who carry for “personal protection” but are a little too trigger happy. Plus stuff like legally owned but carelessly stored etc.

I think I found an additional fertility issue.

I didn’t see it, I just counted and went with tge 80s hint.