Yes. Most people do this! Aligning your body language is a way of communicating general agreement, both intellectually and emotionally. It's usually subconscious, but you can do it on purpose.
Yes, relaxing this is a good way to exercise independent thinking. You can make the choice whether you prefer to build rapport or assert independence each time you interact with a person by choosing to mirror or not.
http://psychologia.co/mirroring-body-language/ http://westsidetoastmasters.com/resources/book_of_body_langu... http://www.theemotionmachine.com/the-unconscious-influence-o...
Yes, relaxing this is a good way to exercise independent thinking. You can make the choice whether you prefer to build rapport or assert independence each time you interact with a person by choosing to mirror or not.