After my webinar a couple of weeks ago, Kathleen Saviers emailed me and asked why, if I love fingerprints so much, am I glad to be retired.
Max Planck, a leading German physicist of the early 20th Century, commented in 1917, “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.”
I like to put it more bluntly: “Old scientists never change; they just have to die.”
When I first got into fingerprints, the idea that “there is no minimum number of points” was just being accepted. I was part of a “new generation” that grew up with that concept. The old timers firmly believed in the mandate for “8 points,” or whatever magic number they had been taught. For my generation, though, David Ashbaugh defined “Ridgeology” as a balance of quality and quantity of detail, not just quantity alone.
Then along came DNA, and lawyers and academicians began asking why don’t all forensic sciences use statistics? That idea began to blossom after the NAS Report in 2010. The OSACs were formed and the old SWGs and TWGs were relegated to the history books of the late 20th Century.
In his 1962 book “The Structure of Scientific Revolutions,” Thomas Kuhn coined the term “paradigm shift” to describe the same concept that Max Planck had referred to in 1917. Kuhn says “normal science” is the use of a set of agreed upon rules by which a group of practitioners answer small daily questions. That is a perfect description of latent print comparison. Each comparison is a small daily question.
Kuhn says a crisis arises when a new question comes along that cannot be answered by the old rules. The old practitioners will not change, but new people coming into the business will devise new rules that answer the new question. Then a “scientific revolution” occurs as new people insist on their new rules. The old timers prevail for a while, but as they leave the field (i.e., die off), eventually the new kids take over. The process from the framing of the new question through the final tipping of the scales to accept the new rules is the “paradigm shift.”
Starting with the use of statistics in DNA, the seed of a paradigm shift in forensic science was planted. It has been watered and fertilized by the new practitioners as we old timers leave the field.
I’m a victim of Max Planck’s curse. It is distasteful for me to surrender the rules under which I have practiced for fifty years. I still believe in a non-numeric, non-statistical threshold for identification. And I will maintain that I am entitled to my “opinion” of identification under Rule 702 in spite of the paradigm shift to statistics & likelihood ratios.
That’s why I’m glad I’m out of the field. I’d rather take my dogs to the dog park to play with their puppy friends while I listen to audiobooks, than stubbornly stay in the losing battle against statistical analysis in fingerprints.