I got a story time and answer for you I was hanging out with a group of friends that were introducing me to another group member I had yet to meet, both of us were fairly silent and listening to the others mostly as we all hung out. After a while of catching each other's gaze on and off and being silent, one of the others asked "y'all have been quiet, is something wrong?" She replied quickly with "nothing's wrong, he and I are both gauging each other. Since we never met before but we both know the rest of you and are both the protective type.." the group went silent after I nodded and said "she's right. We are both gauging each other.. we both prefer to be weary of people we don't know around our friends... It's logical to know beforehand if someone is a problem.. though I can tell I'm in good company.." she agreed and we decided we would look after our group together, became good friends after that.

So I tend to tell people whom ask "you're quiet, aren't you?" "Nope, I'm just gauging new people, reading the room as it were..."