[zdc1]

"Assuming rapport" is hugely important for developing and maintaining connections. People often are not sure how they feel about you or where your relationship stands, so they look for hints in how you feel about them. If you are polite and formal, you are telling them the two of you are not close. If you excited to see them and tell you about the hotdog you ate yesterday, you're taking the lead and setting a tone that's close and familiar.

We're basically wired to consider social cues and signals. Maybe 10% of the time we make a logical judgement of "I really do/don't want to be friends with this person because xyz" and the other 90% is just reading/sending vibes.