Barbara, While I don't think it would be unique to Davidsons, it is not all that unusual for a grandfather, father and son to be Masons. I am aware of many such instances and such is the case with myself, my father and my son. However, about the only objective research value that I can think of is that if one finds a Masonic symbol on a grave marker (or other evidence of membership), then there is perhaps a greater probability of the ancestor or descendent also being a member of the fraternity. My guess is that such would also be the case of about almost any fraternity, and it certainly could turn out to be a useful clue. JD