Mailman syndrome or problem-barking while confined
This is one of the topics I address most often in my dog training practice -- dogs that
habitually bark at a door, window, fence, or noise. Cases involving "mailman syndrome"
actually make up the vast majority of all barking complaints -- and based on the behaviour
I witness every day as I walk my own dog around the neighbourhood, "mailman syndrome"
might be one of the most common behaviour problems period. The behaviour I'm talking about
is when I'm out walking my dog in my neighbourhood, probably two houses on each side of
the street of each block erupt with violent barking whenever my dog and I go by -- almost
regardless of the time and day we are walking by.
One of the positions I maintain is that domestic dogs are not, in fact, descended from
wolves, but that coyotes, wolves, and domestic dogs all descended from African Wild dogs.
African Wild dogs must monitor their whelping area and puppy litter twenty-four hours per
day to defend it from predators and Wild dogs from other packs. Wild dogs from other packs
are not friendly and will kill undefended puppies. Remember this point as it becomes
important later on. This means there are always two or three dogs "on lookout" whose job
it is to bark if they see anything alarming approaching the whelping area where the
puppies stay while the most senior dogs are out hunting to feed the pack. Wolves, coyotes,
and domestic dogs therefore inherited a strong genetic bias to monitor and defend their
surroundings and bark if they see a predator or a strange dog.
Natural selection over time, would eliminate dogs that did not alarm bark and defend their
homes and puppies -- and this is the inherited genetic bias that domestic dogs carry to
this day. Unfortunately, this is quite a common bias among almost every breed of domestic
dog -- and the number of elements that need to be in place in order to trigger the
"syndrome" is very small:
Any situation where a dog is routinely confined with at least a partial, even obstructed,
view of passing traffic is likely to develop "mailmain syndrome" which is characterized by
a steady increase in the degree of barking, duration of barking and/or an increase of the
anxiety, defensiveness, or possessiveness of the reaction over time. The more a dog is
exposed repetitions of passing traffic on successive days, the deeper this conditioning
goes, and the greater the anxiety (barking, pacing), defensiveness (barking, lunging, and
snapping) and possessiveness (oppositional behaviour towards humans) figure in the dog's
Most people don't know this, and get into trouble trying to treat their dog the way they
would want to be treated in the same situation. Unfortunately our two species (people and
dogs) have very different behaviour outcomes based off the same inputs.
If I am left alone at home, I like to have the freedom to choose what I do, where, when,
how and why -- and when I don't have that freedom, I feel less patient, satisfied, and
sociable afterwards. Since we identify so closely with our dogs, that's about as far as
many owners get into deliberating about and deciding how much freedom a dog should have
when left unsupervised. Most people assume that the more confinement a dog experiences
when left alone, the more anxiety the dog will associate with being alone, when in fact,
dogs who experience more confinement, bark less, make fewer anxiety behaviours, and become
less defensive and possessive when they are more confined while alone over time, rather
than the other way around. I believe many owners unintentionally project their own biases
onto their dogs. It's just unfortunate that most dogs are also biased to react badly in
these situations due to the genetic influence of their evolutionary ancestors.
Because most new dog owners trust their own instincts (how can you get through life
otherwise?), they start confining their dog with as much freedom as possible for a few
months, and their perspective only starts to shift as they begin to see the anxiety,
possessiveness, and defensiveness of their dog increasing over time to the point the dog's
behaviour becomes clearly dysfunctional to even a casual observer.
Unfortunately, simply managing the situation to prevent future access to a view of passing
traffic is usually insufficient to resolve conditioning that is already established, so we
must employ a multi-pronged strategy to resolve the issue after it has been conditioned.
The involvement required to implement this strategy increases the longer a dog is exposed,
the later in life you want your dog to transition to not reacting, and how securely versus
how anxiously the dog feels and acts in general. In most households there is also at least
one additional complicating factor present which serves to perpetuate the problem
behaviour, especially miscommunications and misunderstandings that almost inevitably crop
up during behaviour management and training.
Originating on the African savannah
The evoluntionary bias inherited by domestic dogs from the African Wild dog relies in
part, on the fact that different bloodlines of African Wild dogs compete for territory,
and a pack with a size-advantage won't hesitate to prey on the younger members of a
neighbouring pack. I believe this bias may be one of the reasons why dogs tend to mistrust
strange humans approaching our homes. On the savannah, any approaching predator,
reglardless whether it is from another species or your own, is worthy of suspicion.
The theory goes, that a dog's anxiety is piqued when their home is approached by a dog or
a human. Repeated exposures to anxiety triggers throughout the day would tend to erode the
dog's ability resist future triggerings. It's easy to see how just a few days of exposure
in-a-row can lead to a bark escaping. Once a dog barks at an approaching figure, and then
that figure passes by without trying to enter, the dog's anxiety drops. The theory goes,
that it's easy for a dog's brain to pick up a possible threat approaching, feel increased
anxiety, bark by virtue of that anxiety eventually boiling over, and then a marked
reduction in anxiety as the figure passes. There is also the added problem that there are
notable daily exceptions to the "humans pass by when I bark" rule, including: the mailman,
the ups/fedex guy, the flier boy, meter reader, uber eats, where humans continue to
approach the house despite all the barking the dog can muster -- and they persist in
approaching day after day. Each daily repetition of "passersby" (95+%) and "mailmen" (+-
5%) ingrains anxiety, defensivess and possessiveness into the personality of the dog. It's
almost like a perfect storm of genetic bias and conditioning that can easily snowball out
The vast majority of dogs who are crated with no view develop from puppyhood without
barking, destroying things, eliminating indoors, pacing, or self-injuring. The population
of dogs who are never confined, on the other hand has a strong 30+% of their population
who tend to develop these kinds of issues -- and I think there's a causal connection. I
encourage every puppy parent to teach and practice at least two different types of
developmentally-appropriate secure confinement training each and every week -- if for no
reason other than to be sure your puppy is regularly practicing "distress tolerance".
Remember: a dog always trusts the emotions and their related behaviours that it discovers
while following its nose. If we want to change the patterns our dog has developed while
following its nose, at first, we have to manage our our dogs access to the reinforcement
they have become accustomed to, while we train and reinforce the replacement behaviour
(and its associated reinforcements) that we would rather see.
Please check out my blog article on "The three things you have to do to get rid of
unwanted behaviour" for further background on this topic -- and Contact Us if you have any
corrections for or questions about this article.