That is total drivel. Completely.
I am a socialist in my politics - I am strongly left-wing. (That's completely different from "communist", for those Americans who don't understand politics - more like the social democracies of northern Europe, though I am quite left-wing even by Norwegian standards.)
That is /completely/ independent from being a social person. I'm not very social, and never have been.
Political socialism is about wanting your country to be better for people as a whole, rather than for individuals - it's about wanting a state that provides good schools and health care for everyone regardless of their economic state, at the expense of less choice for those with more money. It's about wanting a flatter society with fewer differences between the haves and the have-nots.
That has no relation whatsoever to how personally social a person might be.
It is not more "tribal" - it is aiming for a wider society, which would be the opposite of the closed, territorial and tribal view from the political right. It is not "unhappy" in any sense - nor does it even make sense to talk about the "traditional norms of human behaviour". (Although you could say that anyone whose personal politics differs significantly from the society around them is likely to be less happy - whether the difference is to the left or the right.)
And no, it is not remotely "more afraid". The more right-wing and capitalist a society is, the more afraid people are. Those with lots of money are afraid others will take it from them - criminals, the state, or other people. Those with little money are afraid they are one step away from having nothing - in the USA, losing your job can easily mean losing your house and the whole family losing access to health care. In a more socialist country you have a more even and trusting society, and are safe and happy both with other people and with the authorities and state. And you know that if something goes terribly wrong in your life
- such as losing your job or getting seriously ill - you have a safety net to limit the consequences. That makes you happier, less worried and less afraid.
I don't think you /see/ anything except what you choose to look at in order to bolster your screwed-up views.