The Theory of Structural Dissociation
We find that unfortunately parts of the theory tends to have gotten a bit watered down in this community and wanted to make a post about how The Haunted Self, the book that popularized the theory, actually presented the theory before summaries of summaries of summaries made a lot of people miss what was initially said.
So what does the theory of structural dissociation actually say?
In childhood we start out having action systems. The idea behind these can from the work of Pierre Janet in the late 1800s-early 1900s where he referred to them as action tendencies. The theory of structural dissociation is most heavily inspired by Janets theory. Action systems are any action that achieves a goal, whether conscious or subconscious. What action do you take to obtain food when you are hungry, safety when you feel unsafe, ect.
When there is repeated trauma in childhood some action systems may develop what would typically be considered maladaptive methods to achieve the goal. Such as a common one is while normal action systems in childhood would be dependant on seeking out adults who are their guardians to provide it. If those adults are a source of trauma then a new action system dependant on staying away from those guardians to maintain safety emerges. As these two action systems conflict they can't integrate during normal development. Initial integration happens at around the age of 5-6 for those without developmental disabilities and can be extended to 9 and some say 12 in some cases to account for developmental delays.
Keep in mind here that it is integration not fusion that occurs. The theory goes in depth as to how action systems still present in those who's action systems have integrated normally. A lot of normal things that those with the disorder think they must be experiencing before knowing they have the disorder are normal presentations of integrated action systems. The work or home self, "I'm a completely different person when..." and even the fight or flight response are normal presentations of integrated action systems. But the difference when they are integrated is that the memories aren't compartmentalized and the perspective is still that the singular you did everything even if parts of your personality may have been different with different action systems being more present.
And as we said earlier this is also only the initial integration that happens in childhood. New action systems form and integrate into the whole throughout life whenever you encounter a new scenario that the previous action systems weren't made to handle. You will be put in new situations with new goals and new actions necessary to achieve those goals throughout life. The brain componsates for this in the creation of new action systems.
Another important component of the theory is Apparently Normal Parts(ANPs) and Emotional Parts(EPs) which are two forms of action systems found in those who experience structural dissociation. These terms coined by Charles Samuel Myers in his work on PTSD in the early 1900s and his work the inspiration for this part of the theory. ANPs being action systems that handle day to day life more detached from the trauma and EPs being the parts that hold or are more attached to the trauma. The theory of structural dissociation also recognizes the presence of mixed parts in more complex forms of structural dissociation that have characteristics of both ANPs and EPs to be common.
So what are the complexities of structural dissociation?
Firstly primary structural dissociation. This is present for PTSD and where the recognition that action systems continue to form throughout life and may not be integrated is important. In PTSD, and in primary structural dissociation, a single action system develops that can't integrate into the already integrated whole due to the trauma it developed to handle. This form of structural dissociation presents with one ANP and one EP that intrudes in the form of a flashback. The presence of primary structural dissociation does not disrupt ones sense of self or autonomy.
Now to secondary structural dissociation. This may be the most complicated to understand simply because it encompasses many disorders including C-PTSD, BPD, OSDD and P-DID. While P-DID was not recognized as a disorder at the time The Haunted Self was written the diagnostic criteria for the disorder perfectly describes secondary structural dissociation, in fact describing it better than any of the other disorders in this category from my perspective reading the criteria. Secondary structural dissociation is the presence of a single ANP, typically discussed as being frontbound to a degree, and multiple EPs that intrude in more varied ways than would exist in primary structural dissociation. Secondary structural dissociation can have some effect on autonomy and sense of self though that is more often present in some forms of OSDD-1 and P-DID while those with BPD and C-PTSD still present as their parts feeling like them as a baseline.
And lastly tertiary structural dissociation which is present in DID. This form of structural dissociation having multiple ANPs, EPs and commonly many mixed parts as well. There is significantly less likely to be a single dominant part in this form of structural dissociation when compared to others and the sense of ones autonomy and sense of self are significantly impacted. Secondary and tertiary structural dissociation is based in the initial integration not occurring though new action systems may form later in life and also not be integrated.
Note that since not all diagnostic criteria fully and clearly match the form of structural dissociation they are associated with that the type of structural dissociation one experiences may not always match the disorder they are diagnosed with. This being dispite the general scientific understanding of said disorders and how they tend to be treated medically being based in the type of structural dissociation they are associated with. This is especially true for OSDD as it is a catch all disorder.
The full text linked here if you would like to read further:
manual para el tratamiento de trauma psicologico