What the signal does to your reading of other people

Being cut off used to be dangerous, so a lonely brain does the sensible ancient thing and turns up its watch for social threat.

That has consequences you will recognise. A neutral face reads as disapproving. A slow reply reads as a message about you. Afterwards, the parts of the evening you remember most clearly are the awkward ones, and the ordinary warm parts fade. And before the next thing, you already know how it is going to go.

None of that is you being paranoid and none of it is chosen. It is a threat detector doing its job in a situation where the vigilance itself is the problem.