Sorry for this pattern of posting messages and then disappearing for weeks without posting anything. I have chronic fatigue, and I've been getting lots more hours at my job now, so I spend my time working and then coming home and lying down. I was posting a lot more messages during the weeks when I was stuck at home, underemployed with nothing to do.
I've been learning about socionics. I strongly agree with their theory of intertype relations. It feels much more real to me than the other theories that I've seen of how to use the types to find a good relationship. There will always be people who have exceptions to this and who give examples of great relationships that lasted forever and didn't fit socionics' theory of which ones work best. But I am paying attention to the types in my socionics quadra and have been interacting with some of them, and those are the strongest, easiest, most comfortable interactions that I have ever experienced.
It all depends on being typed accurately the first time around. If you aren't typed accurately, then you can't use the theory very well, unless you do trial and error and try to interact with suspected duals and then semi-duals and other people who are a close match if you changed a couple of the letters. You'd have to use the duals to figure out which type you are and which you are not.
I think that interacting with duals and other members of your quadra is the best way to determine your personality type: it's a test that uses 'doing' instead of self-description. That would be a great test, if some place was set up that required you to test yourself by interacting with duals and mirrors and activators and all that as a way to figure out what your real type is. I think that kind of test would give accurate results. They would use people whose types were already well known, and make them interact with you. It wouldn't be a pencil-and-paper (or keyboard-and-monitor) kind of test. It would be a 'talk to this person' test, or 'the two of you try to cooperate on this goal' test.
There was a long time when I believed this theory: To find a stable long-term partner (for a marriage that won't end in divorce, so that you can have children) I believed you had to get with somebody who has changed all of the letters except the sensing/intuitive letter. And I actually don't remember where I read this theory, whether it was in a book somewhere, or on the internet, or what.
So for an ISTP, your mate would be an ESFJ. That's what I believed for a long time. It didn't help that I have changed my type several times and so I would have been looking for people who were pretty much random and the wrong type, like ESTJ when I thought I was an ISFP, or ENFJ when I thought I was an INTP, and that kind of thing. Some of them would have randomly been lucky matches and some of them would have been terrible, and some would have been just okay. Often I would think that there was chemistry because I found someone's body physically attractive, but I'd have no way to know whether we would get along in a relationship.
Anyway this theory believes that sensing and intuition are so far apart that they can't easily communicate in day-to-day activities in your life, and you'd be more comfortable living with someone who has the same S/N preference you have.
Socionics is different. It has particular intuitives matched with particular sensors, and it also has mirror relationships with someone who has the same S/N preference you do, and all of these relationships within your quadra will work well. The ISTp can go well with a dual ENFp, identity ISTp, activity INFj, and mirror ESTj. Put those four types together in a room and they will create 'synergy,' which is something I remember reading about a long time ago in 'The Seven Habits of Highly Effective People.' There are some other things that you need to make it work, such as a common interest or goal. But anyway this is the best theory I've seen of how to deliberately create synergy, easily and reliably.
When socionics says that intuitives and sensors DO get along well together, it's like joining the soul with the body. In philosophy there has always been this argument over whether the consciousness is separate from the material world, or whether it's some kind of 'material thing' in the world, or what. I feel the same way about separating sensors from intuitives and keeping them away from each other. You have a physical world, and a world of concepts and ideas, and they can never be together. (This 'keep them apart' belief was made worse by my getting my heart broken by a dual in the past and having a 'wow, that was really bad, I'm never doing that again' reaction.)
Unfortunately, this can happen if you work in a job like the place where I work - McDonald's - where every single person there, I think, is a sensor. I'm not absolutely sure about that, and there might be one or two exceptions, but it's almost all sensors. And it's worse because I'm antisocial and I don't go hanging out with groups of people anywhere except at work.
When you put sensors and intuitives together, there will be practical action in the real world and the present time, and it will be guided by a long-term vision. Socionics throws the two together right away without any hesitation, and calls it a 'dual,' and says it's a really good thing, and gives you a couple other people in your quadra that you will also get along easily with.
I'm not saying that each quadra is self-reliant and that they don't need help from the rest of the world, because they still need all the contributions from all the other types. But I'm saying that these quadra groups would work well as a 'household,' a small group of people living together and working on goals together. I've never actually tried it but I imagine that they would be able to tolerate living together as a group better than other mixes of types could.
I am interested in the idea of groups living together because it would be a way to save money and cooperate on household chores if we didn't have 'nuclear families' living all alone, two parents and one kid in a huge mansion that costs millions of dollars, in debt for the rest of their lives, or declaring bankruptcy soon. 'Nuclear families' are partly caused by the government's zoning laws - they are not something that we do because we inherently desire to live isolated from our neighbors. Zoning laws usually don't like groups of unrelated people living together in one house unless they have special permits and inspections and special zones made for them and that kind of thing.
I've learned about all this from researching intentional communities. And when I saw that people within the socionics quadras get along well with each other, my intentional communities antenna went up and thought this was a good idea.