It's a two part question and I'm not drawing the jist of what you're trying to discover.
There is a lot of psychology written about space invaders, and the invaded. Much depends on circumstances. But if people insist on being in your space, cough on them, grab your nose and claim you need a tissue. They'll back up and won't get close again.
If someone is trying to influence you, well, there's ways around that. But thinking on your feet helps.