In family research, I've found that middles names can sometimes lead to the maiden surname of a mother or grandmother.
For example, in my family on my paternal side the surname Baillie was introduced upon the marriage of my great grandparents. On my maternal side, the surname of both grandmothers were used (and still are) in the naming of the offspring. For male children the surname of Willkie is used for a middle name. For females the surnames, Muir Anderson are used for middle names. Wilkie is the maiden surname of my great grandmother who married my grandfather's father and Muir Anderson is the maiden surnames of my my mother's mother and her mother.
First names are interesting to follow the patterns. With each introduction of an in-law new names appear and older names disappear. I've found the first names usually cover about 2-3 generations and then make way for newer names. Occasionally, there will be a throwback to an previous generation. What I've seen are the introductions of previous first names now being used for middle names.
