I think that interpersonal relatedness or 'connection' relates to the degree to which people are willing to have their minds changed, or perhaps more accurately

I think that interpersonal relatedness or 'connection' relates to the degree to which people are willing to have their minds changed, or perhaps more accurately, admit to having their mind changed. Being open to admitting a change of mind requires a certain amount of vulnerability that can be difficult or impossible, depending on how well you know the other person. Anecdotally, I've noticed that in group interactions where time is invested up front in 'ice breakers' (the non-cringey kind) or other exercises where the objective is not about the topic at hand but rather to better get to know the group participants, this can help build interpersonal relations. Seeing others as more 3-dimensional helps with social bonding and thus makes us more open to being more vulnerable.