I was reading through the "Type Changes" thread here and it there are two very obvious camps on whether type is ingrained or malleable. If type is inborn and thus set from birth then that implies there are 16 distinct and only 16 psychosomatic type due to the structure of the brain, VI-ability, ignoring cultural/ethnic/racial boundaries and whatnot.
If type is malleable, then that implies your type isn't inborn and that you can change it through a concentrated effort or through sheer will. Although it's true that your brain doesn't fully develop until you're 25-30, the brain can restructure itself due to continued usage of specific parts of the brain or through trauma. Like most things in biology though, it's you use it or lose it. You can improve say Ne, if you're Ne-PoLR or Ti if you're Ti-PoLR, it would just take a lot of effort on your part.
The truth, like most things in life, is probably somewhere in the middle. What do you think is the effect of your sociotype regarding nature vs nurture?
Also, this brings into question the efficacy of dualization.
For the inborn crowd, it's really simple. There are 16 types and for every one of those 16, there is an opposing "dual" for you whom you will be able to relate with on a comfortable psychological level and distance. Your "dual" would be the best theoretically possible relationship and every other relationship being ranked somewhere beneath that. A hardline stance and it makes the system of intertype relations forever the same for you.
For the malleable crowd, the implications of being able to make a concerted effort to change your type are pretty large. Since Model A relies on a complete systemization of type relations according to your own type, any type changes would necessarily shift your intertype relations. For example: If you typed yourself INTp to begin with then the ESFp would be your dual. However if you went INTp => INFp, ESTp would be your new dual and ESFp would be your new semi-dual. Switching between look-alikes doesn't affect the system too much, but what if you confused yourself for your conflictor? Your whole world would've been turned upside down!
Now it would seem to me that rationals would prefer the opinion that type is inborn, while irrationals would prefer the malleability of types since that implies suitable adaptation. This appears to be a growing rift among the Socion as rationals believe there is only one true dual type and irrationals would believe that you don't really have any "true dual" because you can change your type to accommodate one another.
What's your take on the subject? Do you believe your type is set in stone with one type, one dual? Or do you believe that duality isn't all that it's cracked up to be and as long as both individuals are sufficiently adaptable then your dual may change? Is it somewhere in the middle? What do you think?