I was recently asked how literal/metaphorical I consider the Internal Family Systems model of your mind being divided into “parts” that are kinda like subpersonalities.
The long answer would be my whole sequence on the topic, but that’s pretty long and also my exact conception of parts keeps shifting and getting more refined through the sequence. So one would be excused for still not being entirely clear on this question, even after reading the whole thing.
The short answer would be “it’s more than just metaphorical, but also not quite as literal as you might think from taking IFS books at face value”.
I do think that there are literally neurological subroutines doing their own thing that one has to manage, but I don’t think they’re literally full-blown subminds, they’re more like… clusters of beliefs and emotions and values that get activated at different times, and that can be interfaced with by treating them as if they were actual subminds.
My medium-length answer would be… let’s see.
There’s an influential model in neuroscience called global workspace theory. It says that the brain has a thing called the “global workspace”, which links together a variety of otherwise separate areas, and its contents corresponds to that what you’re currently consciously aware of. It has a limited capacity so you’re only consciously aware of a few things at any given moment.
At the same time, various subregions in your brain are doing their own things, some of them processing information that’s in the global workspace, some of them observing stuff from your senses that you’re currently not consciously aware of. Like you’re focused on a thing, then there’s a sudden sound, and some auditory processing region that has been monitoring the sounds in your environment picks it up and decides that this is important and pushes that sound into your global workspace, displacing whatever else happened to be there and making you consciously aware of that sound.
I tend to interpret IFS “parts” as processes that are connected with the workspace and manipulate it in different ways. But it’s not necessarily that they’re really “independent agents”, it’s more like there’s a combination of innate and learned rules for when to activate them.
So like, take it when an IFS book has a case study about a person with a “confuser” part that tries to distract them when they are thinking about something unpleasant. I wouldn’t interpret that to literally mean that there’s a sentient agent seeking to confuse the person in that person’s brain. I think it’s more something like… there are parts of the brain that are wired to interpret some states as uncomfortable, and other parts of the brain that are wired to avoid states that are interpreted as uncomfortable.
At some point when the person was feeling uncomfortable, something happened in their brain that made them confused instead, and then some learning subsystem in their brain noticed that “this particular pattern of internal behavior relieved the feeling of discomfort”. And then it learned how to repeat whatever internal process caused the feeling of confusion to push the feeling of discomfort out of the global workspace, and to systematically trigger that process when faced with a similar sense of discomfort.
Then when the IFS therapist guided the client to “talk to the confuser part”, they were doing something like… interfacing with that learned pattern and bringing up the learned prediction that causing confusion will lessen the feeling of discomfort.
There’s a thing where, once information that has been previously only stored in a local neural pattern is retrieved and brought to the global workspace, it can then be accessed and potentially modified by every other subsystem that’s currently listening in to the workspace. I don’t fully understand this, but it seems to be something like, if those other systems have information suggesting that there are alternative ways of achieving the purpose that the confuser pattern is trying to accomplish, the rules for triggering the confuser pattern can get rewritten so that it’s no longer activated.
But there’s also a thing where, it looks to me like part of what these stored patterns are, are something like partial “snapshots” of your brain’s state at the time when they were first learned. So when IFS talks about there being “child parts”, then it looks to me like there’s a sense in which that’s literally true.
Suppose that someone first learned the “being confused helps me avoid an uncomfortable feeling” thing when they were six. At that time, their brain saved a “snapshot” of that state of confusion to be re-instated at a later time when getting confused might again help them avoid discomfort. Stored with that snapshot might also be associated other emotional and cognitive patterns that were active at the time when the person was six – so when the person is “talking with” their “confuser part”, there’s a sense in which they really are “talking with a six-year old part” of themselves. (At least, that’s my interpretation.)
And also there’s a thing where, even if the parts aren’t literally sentient subselves, the method still becomes more effective if you treat them as if they were.
If you relate to your six-year old part as if it was literally a six-year old that you’re compassionate towards, when it holds a memory of being lonely and not understood… then that somehow brings in the experience of someone actually caring about you into the memory of not being cared about.
And then if your brain had learned a rule like “I must avoid these kinds of situations, because in them I just get lonely and nobody understands me”, then bringing in that experience of being understood into the memory rewrites the learning and eliminates the need to so compulsively avoid situations that resemble that original experience.