Misuse of Tanner Scale
|PEDIATRICS Vol. 102 No. 6 December 1998, pp. 1494
Misuse of Tanner Puberty Stages to Estimate Chronological Age
To the Editor;
Arlan L. Rosenbloom, MD
James Tanner, MD, PhD
Pediatrics (ISSN 0031 4005).Copyright© 1998 by the
American Academy of Pediatrics Reprint (PDF) Version of this Article
Detective McLaughlin wrote this letter in response to the above letter;
December 16, 1998
Dr. Arlan Rosenbloom
Dear Dr. Rosenbloom,
I saw your letter in Pediatrics (Dec./98) about the use of the Tanner Scale. I am a police detective that works on cases of child pornography on the Internet. If I understand your letter, you state that the Tanner Scale should not be referenced when a pediatrician testifies regarding the age of a subject in a photograph(s). I assume this does not interfere with a pediatrician forming an opinion regarding the age of the subject in a photograph, relying on their experience of examining children. The New Hampshire Rules of Evidence allow for an expert to give an opinion based on his “knowledge, skill, experience, training, or education….” If I understand your letter, this ability to do so would not be interfered with. You want this expert not to form an opinion based using the Tanner Scale, but on other factors such as their clinical experience.
All of this might not even be necessary given that a lay
person can testify about such things as speed, height and age without being
qualified as an expert. A lay witness can testify to his opinion based
on inferences which are rationally based on perceptions, such as the age
of an individual. Expert testimony is generally only needed, and/or permissible
when scientific, technical, or when other specialized knowledge will assist
the jury, or Judge in some instances, to understand evidence or make
a fact determination. Many investigators show child pornographic
images to pediatricians when developing probable cause, a procedure I have
always questioned and felt unnecessary. It seems to me that a panel of
jurors might also be able to make an age determination without expert testimony.
Detective McLaughlin received this reply from Dr. Rosenbloom;
January 21, 1999
James F. McLaughlin
Dear Detective McLaughlin;
Thank you for your very thoughtful letter regarding our communication in Pediatrics regarding the misuse of the Tanner scale. This letter has generated a number of calls from pediatricians who provide expert testimony about child pornography and consider the Tanner staging to be important in their judgment. My response is essentially what you have so lucidly stated, that one does not need the Tanner staging to determine whether one is dealing with a child or a sexually mature individual, and given sexual maturity, that it is extremely difficult to assign chronologic age from the available material. There is a great variability in the timing of various stages, and pubic hair, which forms an important part of Tanner staging, is unreliable for staging Asians and is frequently trimmed or shaved completely in pornography. Pornographers may also prefer to use individuals who appear quite young for their greater prurient interest.
The kinds of judgments that can be made, as you note, can generally be made by lay persons. An experienced pediatrician, however, will have a professional perspective on the range of normality in terms of development for age. The physicians I have talked to are, in fact, circumspect in their use of the Tanner stage, to the point that they really don't need the Tanner stage! Tanner staging is useful for notations in medical records and standardizing observations among physicians and for clinical research. The kinds of judgments that need to be made, however, were made before we had Tanner stages, with no less expertise or accuracy.
Once again, thank you for sharing your perspective. We may need to write a clarifying letter, and your input will be helpful in that effort.
Arlan L. Rosenbloom, MD
C: James F. Tanner, MD, PhD
Reprinted by permission of Detective James F. McLaughlin, October 4, 1999.