Lol hon I don't think you're a sociopath, you wouldn't be asking the question for a start.
I have a similar problem except the opposite happens for me. I'm a confident woman, genuine and forthright, though not tactless, and most people tend to take to me. Yet I find myself being bullied by at least one person in every group I become a part of which then becomes the whole group. I've left jobs and courses throughout my 20s because of it.
It usually happens because I get on very well with people in the group which the one bully sees, doesn't like and decides to destroy that.
It depends what you mean by speaking your mind - there is a way to do it without being hurtful. There's a time and a place for speaking up too. Can you give us an example of when conflict has happened in a group as a result of your honesty and I'll edit my answer accordingly? xx
EDIT: Hi again! Again it depends what you said. What caused the family rift? The only thing I can think of is that you are bringing out into the open things people tell you, which are senstive, whether or not they have told you to say nothing. Like one group member might say to you "I really hate the way X flirts with every guy she meets. She's such tart" Now most of us would say nothing knowing there will be WW3 in the group if X gets to hear about it. Is this what's been happening? Do you feel the need to express these things in the open as you see it as raising trust levels in the group?
If so then you may need some help/counselling on social boundaries & knowing when to be honest & when to say nothing.
Does that sound about right? xxx
EDIT 2! Aha, in that case then I think it might be worth you learning some boundaries. By acting on it you mean they tell you, you give your opinion and they don't like it or they tell you, you give your opinion and then act upon it by bringing it out into the open? If it's the former well the most you can do is be gentler when giving your opinion but beyond that it's their problem. If it's the latter then I think it's your issue and you must learn when to say nothing! I agree with the poster who said you are an idealist. They're very correct when they say some things really are best left alone. Especially between people.
This kind of extreme honesty is common with Aspergers people (a form of Autism) I don't know if you've ever been diagnosed with anything like that but it's worth a mention!
What do you think? xxx