The key to getting to an INTP's emotional core is making it a safe thing for them to do... (Especially for the Male INTP but also true for our INTP Sisters.) Dealing with emotion not something we are comfortable with because of the energy that is there. Dealing with emotion is something that represents pain to us and generally in proportion to the level of energy present. Of the few times where the inner me has been allowed "out of the box" it has not been well received by those around me... the result is that the "box" just gets harder to open each time.
Last time, I relaxed I was ambushed and nearly kicked to death. So you ask why I am reticent.