Hello Mighty Mom
Sorry I took so long to respond. To answer your question "How can you tell when some is very extreme and laid back at the same time?" This type of person is stands out quite a bit. Although some are harder to figure out. I would say they are usually quite animated with their actions, they don't seem to follow though with their actions all the time, especially the boring (no fun stuff) Very extreme people are get excited about entertainment and are influence easily. They have very exaggerated ideals and can make mountains out of little things. Being laid back is a symptom of excitable, they enjoy having fun with their friends and make on the spot decisions.
This off course is not always the case because people learn to control themselves as they grow older. However they usually display little signs, if not all of the actions I mentioned.
I hope this helps. If not let me know