Damien Broderick (
Mon, 22 Sep 1997 12:37:34 +0000

Hi Joao

At 06:56 PM 9/22/97 -0700, you wrote:

>I don't know (or knew) what negative feedback is, some of you also
>disliked this, I still don't understand why

>There is actually a phenomenon called feedback inhibition that occurs in
>enzymes but from there to knowing what negative feedback is, with only a
>few knowledge of economy, goes a long way.

Just to deal with this one point:

`Negative feedback' is *not* primarily an economics term, but derives from
systems and control theory and has very general application. It is at
least 50 years old, and is the basis of all advanced control systems.
Perhaps it is called something entirely different in your own language, but
it is defined in most English dictionaries. I keep a dictionary on my
desk, and another on my kitchen table, and when I see a word I don't know I
look it up - I don't start by asking other people. If it's not in the
dictionary, I look in the encyclopedia in my study, and if it's not there
*then* I have no hesitation in asking.

The reaction your comment elicited (from me to, I must admit, as I stared
in disbelief at the screen) was rather as if you'd suddenly announced to
the members of an astronomy list that you didn't know the earth orbits the
sun. This is very unfair to you, of course, but most of the people on this
list (as Lee mentioned) are information/computer specialists, or scientists
of some sort, and feedback is one of the fundamentals of their trades.

Is that enough to make people cross? Perhaps not. Here's an additional

The term is regularly abused in the general English-speaking culture. New
Age types, and many others, are always smiling gratefully when they receive
what they call `positive feedback' (meaning, for them, encouragement or
praise) and recoiling from the dreaded `negative reinforcement' (meaning,
they suppose, disapproval). In fact, positive feedback is nothing more
than returning a part of the system's output in such a way that the output
*increases*, while negative feedback uses part of the system's current
output to *restrict* or *lower* continuing output. (So, in a restricted
sense, smiling at each other *is* `positive feedback', since it makes us
feel good and improves our mood.)

But if you are being rhetorically beaten savagely about the head by angry
extropians, or literally by nasty thugs, your cries of apology can act as
negative feedback to the social interaction, causing them (we hope) to beat
you less cruelly. If your cries merely excite their rage and blood-lust
(as often happens with attackers, I'm told), this would be positive
feedback that would get you beaten shitless. Not at all `positive' in the
usual meaning of the word.

I realise you know all this by now; I'm just trying to convey the
complicated kinds of annoyance your innocent request for information
triggered. :)

Damien Broderick