Frontal lobes or not ... If you are old enough to hold a driver's license, you are expected to know right from wrong.
Couldn't agree more. The studies on which this "they aren't mature until they are 25" are entirely based on current crops of US students. Students. Not the general public, even.
When I first began research of this type (at a VA hospital 37 years ago), we saw brain differences between veterans who were 18-19 when they ended up in psychiatric care and those who were 30. However, the only thing that neuroscientists are looking for in terms of brain maturity is a relatively stable physiological state. The brain remains somewhat plastic until 25, but is pretty much dialed in by 14.
The fact that American youth (we had Puerto Ricans, Native Americans, Chamorrans, Mexicans, Guatemalans in our studies) were slower to stabilize was known - but the age was more like 20. Military service speeds up the process (I know some of you are saying "doh!")
Inner city kids were more "brain mature." American youths from working and middle class backgrounds reached brain stability more slowly (middle class = slowest).
This research has been replicated, it's a known fact that when we say "American youth are immature until 25" that we are describing an acquired, not innate, state. This explains how youth in India are able to be on their own at 14 (sometimes never seeing their families again, making their own decisions for life). Or in Russia (where the expectation is that 16 year olds should be in the brain stable state). Or China.
Or most of the world, obviously, having named those countries.
It's not innate in the human species to be immature until 25, it's an American thing. We produce that.
All that being said, HH seems to be a typical American teenagers. Should the courts bend to this new-fangled way of raising teens?
I don't know the answer to that. As a jury member, I don't think I could bend that far.