When writing a memoir or family history, you will inevitably come across bits of information that you want to include, but which you cannot verify. Once you have ascertained all the facts that can be checked, other truths may become evident. But these truths may not be of the sort that anyone can authenticate. For instance, you believe your parents were not in love with one another. Can this be proved. Not likely. All you can do is infer the truth.
1) Include these inferred truths in your memoir. These truths can flesh out your stories and add meaning which would otherwise be lacking.
For instance, your parents were married in 1930. Most young couples are without solid financial backing when they start out. Your parents, as much as you (and anyone else) knows, didn’t have any “rich uncle” to ease them through these first years. Are you justified in concluding they must have felt the effects of the Depression during their first days together?
You can’t “prove” this, of course. If, as scientists do with their theories, you proceed as if your hypothesis were true–that your parents must have had a lean time of it then–what insight does this assumption give you about decisions they made during those years, or about attitudes they held in their later life together? Interpretations like these, based on reasonable inferences, can make another person’s life more understandable and your portrait more full.
2) As you include your interpretations, always attribute them to yourself by attaching phrases like “If that were true, it seems to me that…” Your interpretation or inference will take its place as a possible truth in the story you are writing. Although it is essentially different from verifiable truth, the inferred truth has a rightful place in your writing. Without it, your story will be more slight.
3) As you allow yourself to arrive at conclusions in this way, be sure to recognize cliches. These are the ill-fitting shortcuts that actually obscure the individuality of your characters. If you find yourself writing, “Everyone in those days was like that,” let the alarm bells go off! You have left the firm ground of inference behind and are tromping into the sloppy swampland of cliche!