Mind ≠ Identity

Can two minds merge into one, given enough connectivity? Can we create a machine or man-machine hybrid that behaves like two individual minds for certain things but like a single mind for other things?

I raised the following questions and couldn’t fully answer them:

Where is a mind located? Is a mind associated with a region of space? Which space? Where’s the boundary of this region?
What does it take to expand or shrink a mind?
What does it take to merge two minds? Is it possible at all without killing one of them?
How to quantify consciousness? Does it makes any sense at all?

I looked into reports of dissociative identify disorder (DID, formerly known as multiple personality disorder) in the hope of finding examples of ambiguous boundaries between minds. Here’s what I learned about subjects suffering from DID:

At a given time, one of the identities has full control over the body. It decides all the ordinary actions. There’s no sharing of control between multiple identities. Whichever identity is active has full control over the body.
The identities in the background may or may not be perceived by the active identity as “voices”. If they’re not perceived, there’s still presumably some brain activity devoted to them but they’re unconscious.
Memories are private to each identity. This causes gaps in the recollection of events by the subject, which is in general a problem for them. Perhaps, it could be considered successful if the goal was to forget a traumatic event by having only one identity remember it.
The identities share many skills, including motor skills, language, etc. However, an identity may possess its own refinement of those skills such as a particular accent.

I concluded that there’s no clear definition of the mind in the context of DID. The subject’s brain and body host multiple identities, only one of which is in full control or “conscious” at a given time. This makes consciousness a property of an identity rather than a property of a mind. This also opens up the possibility of minds without an identity and without self-awareness.

Then there’s sleep. Outside of dreams, not a single identity is active. During dreams, a pseudo-identity exists. I haven’t studied this topic but it’s more evidence that there isn’t a necessary 1:1 mapping between identity and mind.

An identity is an emergent property of a mind. A mind can have multiple identities, and possibly none. It is unlikely that multiple identities be active simultaneously given that an active identity consists of:

full-body control
a recollection of its own past events
knowledge built upon these past experiences

This distinction between mind and identity relegates the mind to a more mechanical role that’s independent from the question of consciousness. The original question becomes “can two identities be merged into one?”. Answer: merging identities is probably tricky. Splitting off identities is possible and seems easier.