Gripes with the Theory of Structural Dissociation & The community's treatment of it
Essay , september 8 , 2025
One of my more controversial opinions in the online DID/OSDD or general Plural communities is that I don’t entirely buy the Theory of Structural Dissociation, often shortened as the TOSD. The Theory’s mainly talked about in the book The Haunted Self, written by Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart. The theory works heavily upon the past work of Pierre Janet, who was a French psychologist who studied dissociation. In incredibly layman’s, simplistic terms, the Theory of Structural Dissociation posits a couple of main things:
It states that all children and people are born as fragmented, unintegrated parts, and later integrate into one distinct personality. When there is severe, repeating childhood trauma, these unintegrated parts can build up dissociative walls between each other, and fail to integrate into one distinct personality. Interestingly, The Haunted Self discusses the origins of the term dissociation as originally meaning “a division among ‘systems of ideas and functions that constitute the personality,’”(Janet, 1907, p. 332, as cited by Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart, p. 41) Specifically, the book discusses that the divisions among ANPs are caused by a failure to integrate the “action systems of daily life” (Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart, 89) while being chronically retraumatized. Action systems are described by the book as, put simply, categories and systems of actions that we take in order to continue living. These may be thought of part’s roles, like a caretaker engaging in the caretaking action system.
There are two different main types of parts: ANPs and EPs. ANPs are “Apparently Normal parts of the personality” while EPs are “Emotional Parts of the Personality.” These terms were actually claimed by World War 1 era psychologist Charles Samuel Myers. According to The Haunted Self, ANPs typically go about daily life as normal. They typically are hosts, caretakers, etc. EPs are the opposite, described as “fixated in the action system.. or subsystems that were activated at the time of traumatization.” They’re often protectors, persecutors, traumaholders, etc. ANP parts and EP parts are described, explicitly, as “unduly rigid.” (Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart, 17)
Structural dissociation is not exclusive to DID and/or OSDD. BPD and PTSD also fall under the category of structural dissociation. There are different levels to structural dissociation: Primary structural dissociation includes “a single ANP and a single EP.” Structural dissociation has multiple EPs, but still a single ANP. In the text, the example used is EPs in a patient with C-PTSD and BPD that have different trauma responses; One is fight, one is freeze, one is hypervigilant, and one which is hyperdependent. Tertiary dissociation, which is often described as DID, is a level of dissociation in which “inescapable aspects of daily life have become associated with past trauma” or “the functioning of the ANP is so poor that normal life itself is overwhelming, new ANPs develop.” Simply, multiple ANPs and multiple EPs, with strong elaboration and “actual or perceived separation.” (Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart, 18)
I don’t want it to come across as though I think the theory is complete malarky: I do agree with it in many of the most important areas. I agree with it in many of the main components, and the theory is the leading theory for a reason. I have a couple of gripes, though, particularly with the lack of concrete statistical proof behind many of the claims. Obviously, it’s very difficult to prove that childhood trauma will cause someone to fail to integrate, but I do wish there was a bit more concrete evidence provided in the text. I also believe that some parts of the theory don’t make much sociological, anthropological, or psychological sense. My main complaint, however, is the claim that the majority of people integrate into one distinct personality when not exposed to trauma that disrupts their action systems. While they obviously, most oftentimes integrate in the sense of cooperation and low levels of elaboration / “emancipation” between parts, it makes absolutely no sense to believe that they all become one fused part. Everybody has parts, it comes free with your personality. (Richard Schwartz, No Bad Parts.) It may be because of my intense love of the IFS model, but even so it just seems completely ridiculous to claim that only structural dissociation causes distinct parts. I'm also not entirely certain how I feel about some somantic components, namely the "mental level" concept. Though, I understand the intention behind it as another way of describing one's window of tolerance. I also have to add some annoyance with the terms for parts used. I don't know, a lot of it just seems incredibly outdated. Obviously, it's written for people with DID in mind, not Plural people, but it still irks me a little!
While I have a few nitpicks with the theory, it’s obvious that my frustration with it lies mainly with how it is used by the community. Many seem to preach it with little to no nuance or general thought behind it, believing the theory to be completely true, oftentimes without even reading the theory themselves. Oftentimes, it's brought up as “proof” that systems, defined here as multiple distinct entities existing in one body, can only be brought about and created through severe, repeated childhood trauma. A problem with this train of logic, however, is that even if the Theory of Structural Dissociation proved that systems were formed via. the lack of integration of parts caused by this severe childhood trauma, it would not disprove other pathways and mechanisms of system creation. The Haunted Self also explicitly states that often patients may be dissociative in their personality but not have a DSM diagnosable dissociative disorder, (Ellert R. S. Nijenhuis, Kathy Steele, and Onno Van der Hart, 29)
Overall, I think that the Theory of Structural Dissociation is a good start. It's incredibly helpful in explaining different types of parts and formation of new ones, but I have a bit of nitpicks. I just wish that the DID/OSDD community online would actually read their sources before they started spewing bullshit on the internet. I also wish that people would be a bit more critical about the information they're consuming. Though in science, theories are typically well backed by research and, more or less, proven, in psychology it seems the term is completely different. Overall, please remember that The TOSD is a VERY educated guess. It is not the end all or the be all.
Also, not to ad hominem, but Onno Van Der Hart lost his license permanently for life after abusing one of his clients. He can literally never practice psychology again. Other plural people, such as the founder of Power to the Plurals, have come out with their experiences with him. Something I find interesting from the Stronghold System's video is that when asked a question about his research and his evidence, he stated that it was only from his own clinical experiences.....
Sources worth checking out that I didn't directly mention here:
"Problems with Structural Dissociation"
The Dissociation Theory of Pierre Janet by Onno Van Der Hart