I found my youngest daughter slouched down and practically lying on a living room chair one day when I decided to talk to my children about proper posture. I can remember when I was younger always finding every way, except the proper way, to be the most comfortable way to sit (or slouch). So after talking to my children they all decided to demonstrate for me the proper way to sit on a couch.
As you can see, I still have my work cut out for me. (I love that my kids have a sense of humor).