Place a ferret in front of a burrow opening and most will rapidly enter
it to explore; an act that is purely self-initiated and a signpost of
curiosity.  A polecat will also enter the opening, but may show some
initial hesitation at first, maybe some cautionary retreats, perhaps just
sticking their head in and waiting.  The reason for the ferret's reaction
is the hundreds of years of selected breeding where ferreters tended to
cull those animals hesitating to go down burrows, favoring (and breeding)
those that would plunge right in.  Even modern authors of books on
working ferrets suggest only using (and breeding) those ferrets that
"enjoy" their work, as shown by a lack of hesitation in rushing down
potentially dangerous burrows.  The obvious conclusion is that ferrets
have been bred for characteristics that have enhanced their curiosity,
meaning, of course, "self-initiated, non-reactive exploratory behaviors".
 
I realize some people might ague this distinction between inquisitiveness
and curiosity is arbitrary; many animal behaviorists think so as well.
But consider your own reactions.  Imagine it is late at night and a
sudden loud noise is heard in your kitchen.  Many of you would be
startled, and most would creep down to the kitchen to see what caused
the sound.  Is that curiosity?  I argue it is not; rather, it is an
evolutionary exploratory behavior designed to ascertain danger.  While
looking for the source of the sound is an exploratory behavior, it wasn't
self-initiated (the exploration was caused by a sound, not a desire to
explore) and it wasn't non-reactive (the exploration is a reaction to
the sound, again, not a desire to explore).  Contrast that experience
to walking in the woods and finding an old ruined house.  How many of
you would creep inside?  THAT is pure curiosity, self-initiated AND
non-reactive.  While both exploratory behaviors look similar to the
casual observer, it is clear the intent of one is to ascertain danger,
while the other is to explore the unknown.  In a limited environment,
such as experienced by most ferrets, it may be extremely difficult to
judge if an exploratory behavior is self-initiated or not.  That makes
those sorts of observations unreliable; you might be seeing a
self-initiated, non-reactive exploration, or not.  You just can't tell.
 
Bob C
 
[Moderator's note: Bob C. also forwarded a diagram to me.  I'd guess he
meant to post the caption but found he had exceeded the three-post/day
limit.  So I'm adding his caption and the link here.  BIG]:
 
Bob C. says:
While inquisitiveness and fearfulness are different emotions, they are
inexorably linked in the expression of curiosity.  Curiosity is the
self-initiation of non-reflexive exploratory behaviors, but the degree
to which curiosity is expressed is a combination of both inquisitiveness
and fearfulness.  In the graphic, curiosity is shown to pivot between
inquisitiveness and fear so that high fear reduces overall curiosity (the
self-initiation of non-reflexive exploratory behaviors), and vice versa.
Because the expression of curiosity is the simultaneous expression of
both fearfulness and inquisitiveness, it may be difficult to determine
if high curiosity is due to diminished fear or increased inquisitiveness.
Breeding for the expression of curiosity may decrease fearfulness,
increase inquisitiveness, or some degree of both.  Two animals may have
identical degrees of inquisitiveness, but the one with decreased
fearfulness will usually express a higher degree of curiosity than the
other, at least initially until fear is overcome in the other.
 
In the case of polecats and domesticated ferrets, the apparent increase
in ferret curiosity is probably due in large part to decreased
fearfulness, with some minor degree of increased inquisitiveness.
 
http://homepage.mac.com/billgruber/fml/curiosity.html
[Posted in FML issue 4306]