I think of head fix as if you were a windup doll where would the energy go? Both 5 and 7 fixers use their head fix energy to indulge themselves...internally and externally respectively...while 6 fixers use their head fix energy for more serious/sobering purposes.
6w5(sw5w4)...most serious thinking style...better come prepared...greatest scrutiny of the interlocutor...feel that you have a certain amount of time to communicate your case effectively before your arguement loses credibility as that's a good indication your arguement is BS and not worth exploring further. The most focused on ferretting out BS of the six tetrad but also the most likely to come to premature conclusions. In the absense of effective communication does not like to take leaps so defaults to a reductionist interpretation or projection to start with while pressing for better communication to interpret further...like all six fixes assessing tendencies more than the creating and exploring tendencies of five fixers...more use of interpretation substitutes than theorizing. Also reluctant to leave things unsquared that don't make sense or that don't add up. sw5w4 causes a tearing away of the irrelevant and peripheral to get to the truth underneath...hence the mental intensity.
6w5(sw7w6)...a less mentally intense thinking style than sw5w4...not as offensive-minded in getting to the truth. They know there is a lot of BS out there and are never quite sold on what people tell them...but while they want to know what led you to conjecturing what you are conjecturing...they are not as doggedly determined to get to the bottom of everything like their sw5w4 sibling. They will scrutinize you but they will pick their spots more...as much as you are a source of skepticism you are still a source...and they are the most source-dependant head fixers due to using external authorities' views to buttress their interpretations more than their own reductionism. If you don't communicate effectively enough after a certain amount of time and therefore don't pass their smell test(6w5)...they will simply write you off and fly away(the more live and let live and go look somewhere else sw7w6) as opposed to putting your second-rate perception underneath theirs(the more annexing sw5w4).
6w7(sw5w6)...a less focused and more distractable thinking style than either of the 6w5 fixers. They are the most reluctant to come to premature conclusions and are the most open-minded to considering contrary evidence. Compared to 6w5 fixers they have a disorganized all-over-the-mapness and more likely to conjecture multiple things simultaneously. They are more concerned about emptying all the thoughts out of their hyperactive mind without forgetting anything than about being precise and discerning enough...like hurredly jotting down dreams before they forget them. 6w7(sw5w6) fixers are not as confident in their perception as 6w5 fixers so to be on the safe side(6w7)...they list all their thoughts on the matter even the most anecdotal ones just in case as connections and insight often surprisingly come from the anecdotal...which "confirms" that they can't prejudge where answers will come from(sw5w6). This is how 6w7(sw5w6) fixers although more scattered than 6w5 fixers "accidentally" come up with creative ideas that may be overlooked by more structured thinking.
6w7(sw7w8)...the most suggestible/least strong-minded of the 6 tetrad due to the lack of any fiveness in their head fix. Of the 6-fix tetrad they are the least confident in their perception and most likely to depend on someone else's thinking. The lack of any 5ness in their head fix also explains their greater emotional intelligence enough...as they are better able to assess interpersonal situations than any of the other 6 head fixers. Due to their sw7w8 on top of their 6w7 nerves getting the best of them...their thinking style has more of a frenzied energy pattern that's the most likely of the 6 head-fix tetrad to get out of hand and betray them...may be partly why they have a knack for making their nervous thinky energy a shared experience with those around them. The least analytical and most "human" perception style of the 6 head-fix tetrad...most deceptively intelligent...like the most likely of the 6 head-fix tetrad to have their intelligence underestimated.