My favorite concept from Kaplan's Depth and Complexity is Ethics (yes, I know it makes me a total GT nerd that I have a 'favorite' icon :). I love teaching it because my little ones come in with no sense of how to have an opinion. When you ask a question, they look to you to see what answer you want them to say. They say what they think they are supposed to say. It takes quite a few discussions of me playing devil's advocate to realize there is no right or wrong answer. Also, often the justification they make for their argument is "because". Every day I ask them a question and have them turn to their partner and discuss it--they are getting better at it!
So we are reading the Wizard of Oz. And in that story the Tin Woodman and the Scarecrow have a debate of their own. They argue what is more important having a heart or a brain? So I asked my kiddos to answer the same question:
Love the detail of the hearts inside...even the dog! :)