Once a month, a group of family history researchers from New Jersey, Pennsylvania, and New York (and sometimes Delaware) meet in Voorhees, NJ, as the Irish American Family History Society. (IAFHS) The formal name belies a casual, fun atmosphere with great craic! Our June meeting had a titillating topic: "Tales and Taboos." We shared stories about our ancestors, stories which were often covered up by family members. We discovered that knowing and researching these stories are important because they can either help or hinder our research. For example, I had an ancestor listed on a census as a widow, with one child, living with her parents. So, I began digging. Turns out that she was not a widow--she and her husband fought frequently early in their marriage, and she left her husband often. I guess she was pretty mad at him the day the census taker came! But if I hadn't dug into family gossip, I would not have discovered the error in my records!
I will list some of the common "tales and taboos" that might create brick walls in our research. Often, there is an explanation for why we are thrown off track, and that explanation makes for a great tale!
MURDER AND MAYHEM! I've met quite a few researchers whose ancestors were murderers or murder victims. Not all of these homicides resulted in convictions. Sometimes they were listed as "accidental deaths," especially if they happened in a workplace or tavern. Many times, our ancestors died in workplace accidents or catastrophes that would be considered criminal today. Don't forget to check death certificates for any hint that a coroner's inquest might have occurred. You might be able to obtain the inquest records or find newspaper articles about the circumstances surrounding an ancestor's untimely death.
KISSING COUSINS! The degree of relationship acceptable for marriage has changes through time and place. In many societies, marriages between first cousins and between uncles and nieces were accepted. Bigamy was not limited to the Mormons--I have heard many stories from researchers who found that their ancestors had two or more spouses without getting divorced. Can't find a marriage record for your great grandparents? You might consider that they might not have bothered making their relationship "legal!"
BUN IN THE OVEN! My vote for the all-time-brick-wall-making-event is birth date. Children conceived by or born to unmarried parents have been the subject of fudged dates and relationships on many a family tree. Consider this possibility when there are large gaps in the sibling order of a family--the "bonus baby" may in fact be a child of one of the daughters.
DON'T BE AFRAID TO INQUIRE! I have found that some researchers are embarrassed to consider the idea that an ancestor might have been "scandalous," but an open mind often leads to genealogical discoveries.