Entirely off the top of my head, wouldn't the best benefit of having an alternate personality to be able to adapt faster to different situations? You mentioned this slightly, with the idea of an ENTJ to work, and an ESFP for social situations, but if you were able to, the best possible way would be to create a personality for each individual situation, to help you deal with it in the most efficient way.
As for the second part, I have no idea. I guess it would be possible, based on the idea that a personality is based on our experiences, but I'm not sure that it would be enough of a significant change to provide much benefit, or if you could develop a variety to change between at will.
I guess that by constantly forcing yourself into thinking in a different way could cause some change, (I'm picturing trying to force a pessimist into acting optimistic) but even then, there's still a chance of the original personality coming back. Not all aspects of human nature are flexible, so depending on what particular aspect of personality that you wanted to change, some parts of it may be possible, but I don't think a complete personality change would ever be possible.
I think that if you /did/ try and change your personality completely, it would just be a mask. You could ignore your personality, try and act completely different, force yourself to think in a different way, but I think that eventually this would fail, and you'd mess up and forget how to use the mask or something, since I can't work out how to carry on with that metaphor anyway (My idea is more of you letting the facade down, and not quite being able to hide your personality completely). If you did it slowly, part by part, then I think you would have a better chance at a permanent change.
(This is all entirely guesswork though, feel free to ignore me completely =P)
Well, I didn't really have
changing ones personality in mind, so much as adding new ones 'on top' of the existing one, the way that someone with DID has - although, for them, it's usually a coping mechanism brought on by childhood trauma.
Think Tyler Durden from
Fight Club. Or even John Cusack from
Identity.
This new personality would not really be "you" but another personality that could "take over" your body when it's needed.
I assume one detriment could be that the personality might have too much a mind of it's own (it might hate the real you, or want to permanently take over the body, or cause harm to you in some way) but I'm assuming that, if one is consciously generating a secondary personality, they can mold it to be what they want.
I think that acting as an ESFP or an ENTJ would be just that, acting. I don't think that it would be possible to honestly change a personality fast enough to take advantage of those situations, but there's a better chance of managing to drag out enough aspects of those personalities to act as them for a while, which could be close enough to make a mask to let you act as one of them, but not exactly enough to honestly create a real personality. There's also the question of it you /could/ change between them fast enough, or notice the opportunities where one personality might be better than another, or which one to change to if you know that it's not working at the moment.
I would see it more like having the other personalities lying dormant until the real "you" triggers them to come out. With Dissociative Identity Disorder, the alternate personalities are tantamount to completely different people, with their own beliefs, memories, and mannerisms sharing the same brain.
The article I linked to in the OP talks about how people with DID have different brain activity while different personalities are "in control".
I think that the benefit of being able to adapt faster to a situation speaks for itself, as I think this could be useful if it was possible and if you were able to adapt and change fast enough. However, I do think that the idea of my mind sort-of collapsing under the pressure of having to maintain two or more personalities would be a bit of a drawback. I'd rather have one fully-functioning personality, than a fragmented mind of several personalities.
The thing about DID is that each personality would adapt in it's own way, depending on what it experienced while "in control", independent of the original you. I suppose the point of generating new personalities would be so that one would not have to adapt - the splitting of ones personality would be the adaptation, having 'different people' that could handle different situations in one body.
If I wanted to attempt this, I'd start by creating a personality in my mind, almost like a character in a story, then force myself to act more and more like them, until that became the natural way of doing things. I'd also try to auto-correct my thoughts until they became closer and closer to the thoughts I would predict the alternate personality/character having, until they too became natural.
I partly agree. I think the first step would be creating a character, figuring out every aspect of them, giving them a back story etc. But, instead of acting like them, start talking to them as if they were a separate person. Have them sort of take on a life of their own. They would essentially be an imaginary friend, but you would have to attempt to relinquish control of them - there would have to be some 'give and take' in your discussions with them. They would have to be their own person.
After a while, you start letting them handle things for you the same way a real friend would, but they use your body as the medium. I think over time, if you were able to convince yourself that this character is real, and that it's
them and not
you that's using the body to interact with other people, over time this other personality would produce it's own neural pattern in your brain, and just like someone with DID, it may be possible to switch between patterns.
And if I did create a personality, I'd try to create one that doesn't get bored with talking about reality tv shows and clothes all the time. I think that would come in handy at school. Or one that can actually focus for more than ten seconds at a time.... or one that actually makes sense at any point, which would also be really useful, I think. =P
This sort of makes me wonder how much different someone would want their creation to be from their original self. I'd want to retain some essence of my original personality in my alternates. Perhaps they have some of my same interests, but are able to go about it in different ways (different learning styles, more motivation to learn, more follow through or ability to apply things etc).
I think it would be interesting to have three other personalities, for a well rounded 'team' of minds. I'd go for the ENTJ and ESFP for the situations I mentioned in the OP. The third would maybe be INFP, but they would be female (it would be interesting).
The ENTJ-like one I would imagine being sort of like House: quick witted, capable of being a leader, and doesn't let people walk all over him. This alternate would be my business personality, the one that would take action when it's required. My original self is fine at absorbing and contemplating information, but this alt would apply it, using quick deductive reasoning and superior strategic abilities.
The ESFP-like one would be the alt that knows how to deal with people. When relatives guilt me into seeing them, or I have to give a speech or some such thing, this would be the one. The primary differences from the original me would be that this alt can partake in small talk, and it's charismatic (I can see my ENTJ-like alt repelling people the same way my original self does), able to make and interact with other people smoothly.
The third one I haven't thought about too much, but why limit myself to just one gender?
