Feedback

'Causality' is an example of an "every day notion" that has penetrated epidemiological thinking for at least 150 years.

I try to discourage my students from thinking about it too much, especially if they think about it loosely.

'Reverse causality' seems to have appeared in epidemiology more recently, perhaps only ~30 years ago, and it is more noxious because it's easier to think about loosely. But perhaps it is more important that it is a within-the-field jargon term that makes it harder to communicate with our public audience.

An early example in epidemiology involved developmental deficits and environmental lead exposure. Thinking ELE-->DD, the investigation faced the possibility that DD-->ELE, as in a disabled child eating paint chips on the window sill of a house painted with lead additives (e.g., added to speed drying of the paint).

Thinking about this possibility from a physics perspective, one faces the concept of feedback and feedback loops, which the public knows something about from first-hand experience (every day notion), if only from watching a Roadrunner cartoon or Three Stooges movie.

Did the epidemiologists use the term "feedback"?

I regret to say they did not.

Instead, they turned to a new jargon-term for the field ( "reverse causality" ) and set us on a path leading away from public comprehension toward a within-discipline conversation.

The next time you feel a need to write down or use the epidemiology jargon term "reverse causality" please return, and re-read this important article on the inadequacy of climate change modeling:

Feedback missing in climate change modeling.

There is no mention of "reverse causality."

Instead, we see the term "feedback."

Hmmm. Any lesson for communication of epidemiological evidence to the public?

Post a comment if you face a situation in which you feel compelled to use the term "reverse causality" in an epidemiology context, but the term "feedback" cannot be enlisted into service of improved communication.

By the way, some of you may recall the pertinent distinction between recursive and non-recursive arithmetic relations, with 'recursive' defined in relation to a sequence of terms in arithmetic as opposed to the apparent temporal flow of time sequences. 

Recursive Arithmetic

Is this memory important?

See: 

Paxton et al., 2011

Is there a fundamental problem created by epidemiology graduate programs that persist in failure to teach principles of simultaneous equations modeling to every student?