I don't mean from a hippy-dippy-trippy spiritualism perspective. I mean, from a cognitive neuroscience perspective: what is a self? I don't think we can find a part of the brain that's responsible for it, so it must be a construct, indistinguishable from self-concept. Moreover, Kahneman's work suggests that there are multiple "selves" with different agendas. If so, what does that imply about identity, agency, responsibility, etc.?
What makes the illusion? The construct? I'm inclined to think the self is part of our wetware along with the influences on our conscious and unconscious self(ves) from our shared experiences with others. We just haven't figured out how to identify or quantify it... yet.
From a strict materialist perspective, I think we can consider it an emergent network effect. But look at other intersubjective constructs like money, language, or national borders. Those things are also illusions, in that we cannot take apart the universe and find the money particles, or language particles, or national border particles, for instance. Similarly with the self. We cannot take apart the brain and find the self.
In order to unpack what an emergent network effect might mean, consider this thought experiment from another reply above:
Imagine a world in which communication stopped. That is: all communication. Not even actions could be discerned. In a world where we would be unable to express anything in any way, nor receive expressions of anyone else in any way, I believe the self would evaporate. Indeed, mini-experiments in this happen at meditation retreats, where evaporation of self happens therapeutically, so that we can learn to control the impulse and modulate it. But what about if we could never get it back?
By the way, I think money, national borders, language and other constructs would evaporate as well, if communication was somehow halted.
My vote for what's behind door #2 is about the self as a discrete thing-in-itself. Of course there's a "self" that is a concept or emergent perception of consciousness, but it is not something we're ever going to see on a CAT scan or something.
The "self" is a word that has partly to do with the organization of one's lower and higher functions. Let's look at a good case, where the brain does not have a congenital defect. The further away from the corpus callosum you get, going more towards the direction of the parietal, occipital, temporal, and frontal directions, the more a person can consider, and that aspect of a person is a bigger adult.
So, is this an illusion?
I think that when we try to take a term with a proven existence, and call it an illusion, it's incorrect.
Now, do we view ourselves accurately? That is tough to do, but important because it has job implications and determines what a person needs, and what they don't need.
I doubt it. Human typology is tough. There are so many personality tests, ability tests, etc. and we leave it to human error to decide that stuff.
Challenging thoughts!
Oh no, I am going to make somebody mentally challenged :x