Well, find your quadra first.
A good way to set about it: the profile of the relative you really like to avoid or don't get on with, that of the members of your 'natural group' back in high school and the rest of the groups where the 'others' were, what nonverbal or minimally verbal cues do you get from strangers that make you like them instantly and exchange words naturally. You've been here long enough to separate idiosyncrasies from IEs.