Semantics
Internal Family Systems is a therapeutic framework for working with different Parts of oneself (also called sub-personalities). It understands these parts as belonging to one overarching Self and focuses on mending relationships between parts, gaining their trust, and freeing them from burdens (trauma, undesired roles, etc.).
Agents are intelligent, goal-focused cognitive entities with apparent agency. They’re similar to IFS’s parts, but tend to be less focused on personification and more focused on optimization of behavior. Agents optimize towards goals.
Plurality is a very broad umbrella. Generally speaking, it refers to any experience of having more than one self in the same brain (though even this is sometimes too specific; experiences of one subdivided self or one changing-in-patterns self can also fall under plurality).
Dissociative Identity Disorder is a psychiatric diagnosis for a particular experience. This experience includes a sense that the other selves in one’s head are “not me” in some capacity, as well as difficulty remembering events experienced by other selves (dissociative amnesia) and the problems functioning expected from any disorder.
Note: These frameworks can overlap- e.g. a plural group may use IFS strategies to work with themselves.
Goals
Internal Family Systems is primarily a therapeutic framework for treating mental illness, changing behavioral issues, or otherwise transforming a person’s state by working with their system of parts to shift dynamics within it. In the words of the IFS institute, its purpose is “to bring more Self leadership to the world.”
Agents are a framework for understanding human behavior and brain structure, particularly in cases where self-sabotage and contradictory behavior are present. They primarily provide explanatory power by viewing these behaviors as originating from agents with conflicting goals and/or optimization strategies, though knowledge of their existence can supposedly help account for their actions (such as by finding ways to optimize for combined goals).
Plurality attempts to create community and language for those whose experiences do not match the normative idea of “one self per body.” The associated community offers chances to meet others with similar experiences, as well as to find resources for getting along with one’s system. It arguably has political goals of expanding acceptance of atypical experiences (similar to disability and LGBTQ+ activism communities).
Dissociative Identity Disorder exists to provide a framework for psychiatric treatment. It offers something to tell insurance, as well as treatment tracks and resources for people with these experiences.
Views of Personhood
Internal Family Systems asserts that parts are not truly separate people; however, some practitioners encourage interacting with parts as autonomous selves, giving them personhood within the larger self they’re seen as part of. That larger self is generally considered to be a person.
Agents are not typically personified; if anything, they’re objectified to their neurological patterns. Apparent autonomy is seen as just that: apparent.
Plurality does not make this assumption of non-personhood; in fact, online communities associated with plurality often encourage the belief that system members are independent people of their own, with all the trappings of personhood coming with that assumption. The plural framework is a radical re-definition of what it means to be a person that allows for alternative definitions of identity. (Viewing system members as parts of the same self is also included under the umbrella, but less emphasized than experiencing them as their own people.)
The plural community further asserts that the psychiatric view of plurality unnecessarily pathologizes differences in experiences of selfhood and dehumanizes system members. It argues that there is nothing inherently wrong about experiencing the world as multiple, separate selves, and that they should not be required to see themselves as parts of a larger self or single person if they don’t want to.
Many modern academic readings on DID assert that all members of a system are dissociated parts of one whole person. As such, alters are not viewed as truly being their own people even if they outwardly appear as such. Instead, they’re understood as dissociated states of consciousness. All differences in behavior are attributed to the resulting differences in access to memories, skills, and other aspects of awareness.
Common Ground
All of these frameworks are different understandings of the same core idea. The mind is not a perfectly unified entity. It’s composed of fractal patterns of behavior and agency and awareness, each piece tying into another piece of the overall pattern to create something larger. Parts are patterns. Agents are patterns. Alters and headmates are patterns. People themselves are nested patterns all the way down.
Sometimes these patterns are closely associated with each other. Other times, they’re kept carefully separated. Whether patterns are associated or dissociated from each other seems to be linked to whether it was adaptive for those patterns to be kept apart or not. If exposing one pattern to another would interfere with those patterns’ ability to be useful, then those patterns are going to be kept further apart than two patterns that work well together.
For example, let’s imagine that a child grew up around a parent who was kind to them sometimes and cruel at other times. The child might develop with more than one pattern of response for this parent:
- One pattern might respond favorably to the parent. It might contain pleasant memories, positive sentiment, friendly behavior, and so on to ensure that the response is genuine and allow an outlet for positive feelings. It’s able to optimize for enjoying the good periods while they last (and possibly trying to extend them).
- Another pattern might respond less favorably to that parent. It might contain unpleasant memories and hurt sentiments, and it might respond by avoiding the parent or fighting back. It has to optimize for surviving their cruelty (and possibly for preventing or escaping anything that might set the other person off).
In cases where that same child were exposed to a consistently loving parent, they might only need to develop one of these overarching pattern of behavior. That pattern would have subpatterns for meeting needs and reacting to the parent, but there would be a high degree of internal cohesion. The child experiences themselves as one person with consistent behaviors.
In the case of a less predictable parent, that child needs to be able to behave in opposite ways depending on their parent’s state. They need to be able to think about the parent differently, react to them differently, and potentially even hide information from themselves to avoid upsetting the parent (“you hurt me!” may not go over well).
If these ways of thinking can be reconciled, then these patterns may still maintain a degree of association. They may still be less associated than if the parent’s behavior were consistent, but each pattern can still maintain awareness of other patterns without that negatively impacting their ability to optimize their goals. The child experiences themselves as one person with conflicting behaviors.
If these ways of thinking can’t be reconciled, then these patterns may need to dissociate from each other to avoid confusion or misplaced behaviors. This is particularly the case when access to information becomes dangerous for some patterns. If the child is aware of the abuse when the parent is loving, then they may upset the parent and trigger more abuse, so it may be more optimal to reject or dissociate from memories of abuse when in their favorable response pattern.
When this dissociation includes rejecting memories, behaviors, skills, and other attributes to the point where patterns lack connections to each other and each pattern has a unique way of understanding and reacting to the world, psychiatry calls that Dissociative Identity Disorder. Research and therapies around DID focus on finding ways to reconnect and reshape patterns to release dissociation created by trauma. In other words, it asks whether that child can learn to access and use both patterns of behavior by choice instead of bucketing everything into one response or the other.
This process of developing and connecting (or disconnecting) patterns to meet different goals is often (but not always) a subconscious process. It’s one that you can learn to notice with practice, however; when you do notice it, it becomes possible to work with these parts of your mind. Further practice may allow you to change the connections between patterns intentionally.
IFS is based around the practice of personifying these patterns to further improve one’s ability to work with them. It’s hard to think of ways to change an abstract pattern of behavior. Choosing to understand these patterns as autonomous agents working to accomplish a goal makes it much easier to understand and change them, making it a viable framework.
Plurality accomplishes similar goals, adding the understanding that personhood doesn’t have to be assigned only to top-level patterns and that it can be beneficial or preferable for some parts to stay disconnected from each other.