It's common knowledge within the field, and most of the studies on it are old (as in 10-20 years old), specifically because the research had already been done, so all that would need to be done afterwards is repeat studies to confirm the originals. Which probably exist, but are tougher to find. What you are arguing against was essentially an established fact (backed by multiple studies I'd have to find again) in my undergrad and post-graduate studies in psychology, including, and in the internships and jobs I had related to applied developmental psychology.
Development of orbitofrontal function: Current themes and future directions
This is probably a bit old for you (2004), but if you're truly interested in it, this article references a lot of different studies from the chronological beginning of the studies on brain development. Which, again if you're truly interested in learning about it, is the place to start. Without understanding the historical context of research, and what's already been determined, a study of, say,
4 groups: Teenager with peers, Teenager without peers, Adult with peers and Adult without peers, playing a videogame involving running red lights while hooked up to an EEG probably won't have all that much meaning while going on about both the tangible results and the different brain activity that's observed. But shows exactly how teenage decision-making and risk-inclination is much more effected by their peers than adult decision-making and risk-inclination.