Submitted by Charlton Stanley (Otteray Scribe), guest blogger
The relationship between mental health and the legal system is a turbulent one at best. One major problem is they speak two different languages. For example, insanity is a legal term found nowhere in any psychiatric or psychological diagnostic manual.
There are several key words used commonly by both professions, but which have quite different meanings. The words “validity” and “reliability” are part of the vocabulary of science. To a scientist, the word validity means that a test measures what it claims to measure. When a test is intended to measure depression or anxiety, the user can assume it measures depression and anxiety.
Reliability refers to the repeatability of a test or measurement. If we give the same test to the same subject several times, all the scores will fall within the standard error of measurement 95% of the time.
When an attorney uses the word validity, it means, Binding; possessing legal force or strength; legally sufficient.
The legal interpretation of the word reliability suggests the subject matter is trustworthy, and that one can rely on it. However, when a scientist says something is reliable, it means whatever is being tested will get the same results with every retest, within the Standard Error of Measurement.
An examination of the literature of both professions reminds us of the quip attributed to George Bernard Shaw, “[We] are two peoples divided by a common language.”
When I was in graduate school, a well-known attorney gave an invited lecture to the student body. The speaker made several sweeping generalizations about the mentally ill; all of them displaying a stunning ignorance of facts. Then he turned his venom on those in the mental health professions, referring to mental health professionals scornfully as, “Soul doctors.” I would like to say people like him are rare, but they are not. I have known judges who, quite literally, did not believe in mental illness. We had one of those in our area who, mercifully, retired a few years ago. People like that remind me of those misogynistic knuckle-draggers who don’t believe there is such a thing as rape.
Now, back to the stormy relationship between the legal system and mental illness.