For me the loner thing is extremely context based, and largely a product of the way I anticipate competency in others. In the city I'm rather gregarious. Yet there I have very low expectations of the competency of others, so I am never disappointed. Everything is light, bouncy, shallow, and rather meaningless. It's about making money, and the types of fun that requires money.
On the other hand, move me into the sticks and I'm shockingly intolerant. My expectations of others are higher, the probability of disappointment more, and woe betide that which is incompetent, irritating, or otherwise disturbs my tranquility. The spotlight of my conscious attention is much more focused, and outside that beam I don't care about anything else. I can suffer few people in such a place. They are just noise.
Interestingly though, 'till fairly recently, I was still happily running a small forum of about 700 members even though I had alternated between spells of gregarious extroversion and frequent two or three days hunker-downs in what has come to be known as my mushroom chamber, while I worked on a task. I'd happily shepherd those 700 along with a smile, but if someone came to the door I wouldn't give them the cheese of your dick. Further, it is also interesting to note that some that might describe themselves as loners here, will happily go online to actively seek out what are fundamentally communities of strangers to communicate with. On that, for most of us, I don't think the loner thing is particular clear cut. True, I'll accept there are some types that are enduringly field independent and apathetic to others across all circumstances. I suggest the rest of us are heavily bound by context, and in some of them just prefer to be left the * alone.
Wildone39, hola
I think the variations between people are large, and the variations within a person over time can be quite large too. However, if you or your loved ones are starting to seriously consider it is getting intrusive, or grossly impairing your normal function, in the nicest possibly way amigo, it could be time to consult an expert friend...