We don’t actually experience reality. We experience our model of reality plus some immediate sensory inputs. The inputs serve not just to fill in the immediate holes in our model but also to update the model as well. That sounds a lot like research. We gather information until we can build up a model of what happened. Inputs that come in after the model is constructed may reinforce the model, adjust the model, or significantly alter the model. When our model and reality have subtle mismatches, the result can be an optical illusion.
The documentary that got me thinking showed an image of a checkerboard with dark and light gray squares. The image also contained a cylinder which cast a shadow across the board. We have no trouble deciding which squares are dark and which are light, in or out of the shadow. Yet the “light” squares in the shadow are exactly the same as the dark squares outside the shadow. We see only partially with our eyes. The rest we “see” with our model of the world. Our model of the world prevents us from being confused by the shadow and missing the pattern of light and dark squares. At the same time our model is fooling us into thinking that the light shaded square in the shadow appears to be lighter than the well lit dark square, even when they are exactly the same. Magicians take advantage of our mixture of model based seeing and actual sensor input all the time.
Genealogical Illusions
How much does our model influence our research? Context can play a big role when interpreting subtle data. Differences in culture between our model and our ancestors actual cultures can lead us to think that things that were highly improbable when they could easily have happened. Does our model tell us that if a record doesn’t exist, then the event that it would have recorded never happened? If it does, is that right or is our model missing some known record loss? Lately, I’ve been working in some records of a court of petty sessions in Ireland. Does a man being no longer recorded in them tell me that he moved away, or does it tell me that he got better at keeping his pigs in their pens, or perhaps that the constable, who perhaps really did not like him, died or moved away? Am I looking at a genealogical illusion?
The cure for illusions, both optical and genealogical, is to carefully check, and not relay on our models when things seem questionable. I have a lot more checking to do in those Irish court records. On the other hand, I’ve already done a measurement on the checkerboard illusion above. The RGB color values of squares A and B are R=102, G=102, B=102 for both. Our model, useful as it is for seeing the pattern, fails when it comes to seeing the actual shade.