I dunno, to me it doesn't seem that much different today than it did 40-some years ago when I was a teenager and had seen plenty of different types. I was raised to be polite and respectful, as were all of my friends. But I also observed plenty of kids who were terrible. I remember one family where both teenaged sons would often tell their dad to get ****ed in front of everyone. And it wasn't some big argument, it was normal conversation. There were no repercussions. Ever. And that was by no means the only family I ever saw where it was like this.
All of my friends have raised their kids right and they are as polite and trouble free as any generation has been.
