One of the steadier findings on what makes people feel close is feeling that the other one is paying attention: that they heard what you said and cared about it. Researchers call it responsiveness. Evidence: decent
A follow-up question is the cheapest proof of it. Not "cool, I also…", but "how did that go?" In speed-dating, people who asked more follow-up questions were liked more and got more second dates. Evidence: decent One caveat from first-meeting studies: men were reliably more drawn to an attentive stranger; for women the effect was smaller and depended on the woman. Evidence: decent So don't perform it. Do it because you want to know.
Same theme: How closeness forms