It never would have occurred to me that everyone can't touch their chin to their chest... You learn the wackiest things on YLF!
From the hand test I'd have an average neck which is probably true, but I also have big hands, so who knows. I do know, from my adventures in altering sewing patterns, that I have a forward neck and forward shoulders. Thus true turtlenecks aren't comfortable for me because they make me feel choked, rather than the height being the issue.
Some of this stuff is genetic and some postural; I've had massage therapists tell me that most people these days have forward neck posture because so many of us spend our days working at computers.