Development in Adolescents
The brief explanation on James Marcia's identity crisis theory was the most interesting section on adolescents in chapter 9 to me. I remember having a very difficult time trying to "find myself" during my mid-teens, so reading about the different statuses of identity achievement was very cool.
An Unpleasant Surprise
I was aware that the suicide rate among adolescents was quite high, but I didn't know that it has grown a staggering 600% since 1950! This somewhat affected me more than other details in the textbook because in middle school I had a very personal experience with a friend's depression and suicidal behavior.
New and Interesting Knowledge
The fact that in adolescence the limbic system is well developed, but the prefrontal cortex is still developing and how this affects behavior in adolescents was a really interesting topic to learn about in my opinion. It really does help to explain why we all act so differently as teenagers.