On My Buddies
Sir Frederick
Dogs aren't stupid wolves; they are much smarter
20 August 2008
NewScientist.com news service
Kate Douglas
IF YOU have ever caught a dog stealing food, you will know the feeling: a sense
that the dog knows it has done wrong and feels... well, guilty. Maybe that's
pushing it - but try telling a dog owner that their pet cannot experience pain,
excitement, love or other mental states we usually reserve for humans. You won't
get very far.
Until a decade or so ago, scientists interested in animal behaviour would have
dismissed these observations as sentimental anthropomorphising. They considered
popular attitudes to pet dogs silly, and saw the animals themselves as little
more than dumbed-down wolves. Above all, there was a widespread view that
domesticated animals in general were "artificial" products of human breeding,
irrelevant to anyone interested in studying real animal behaviour.
How times have changed. Last month more than 200 experts attended the first
Canine Science Forum in Budapest, Hungary, where they discussed, among other
things, what is going on inside the mind of a dog. While still some way from
painting a full picture of the canine Umwelt, their work is making it clear that
our inclination to invest dogs with human-like states of mind isn't as
unscientific as it might appear. Dogs really do have some remarkable mental
skills that allow them to thrive in their strange habitat - our world.
Domestic dogs evolved from grey wolves as recently as 10,000 years ago. Since
then their brains have shrunk, so that a wolf-sized dog has a brain around 10
per cent smaller than its wild ancestor (see "Wild at heart"). That was one
reason why animal behaviourists felt dogs were merely simple-minded wolves. It
has become clear, though, that despite the loss of brain volume, thousands of
years spent evolving alongside humans have had a striking effect on dog
cognition.
Right from wrong
For one thing, researchers are increasingly convinced that dogs must possess
some sense of right and wrong in order to negotiate the complex social world of
people. A pioneer in this area is Marc Bekoff from the University of Colorado at
Boulder, who has spent decades watching animals at play. He has championed the
idea that in many social species, including dogs, one of the functions of
rough-and-tumble play is to develop a rudimentary sense of morality (New
Scientist, 13 July 2002, p 34).
The fact that play rarely escalates into full-blown fighting shows that animals
abide by rules and expect others to do the same. In other words, they know right
from wrong. Bekoff argues that this is a survival adaptation that allows animals
to smoothly navigate other social interactions.
Friederike Range from the University of Vienna, Austria, takes the concept of
dog morality even further. In a series of experiments, her team rewarded dogs
with a food treat if they held up a paw. They found that when a lone dog was
asked to give its paw but received no treat, it would persevere for the entire
experiment, which lasted 30 repetitions. However, if they tested two dogs
together but only rewarded one, the dog who missed out would make a big show of
being denied its treat and stop cooperating after just a few rounds. "Dogs show
a strong aversion to inequity," says Range. "I prefer not to call it a sense of
fairness, but others might."
"Dogs show an aversion to inequality. Some might call it a sense of
fairness"This is quite a claim: even the idea that primates respond to
unfairness in a similar way to people is highly contested. So why would a dog
need such a trait? Range points out that the concept of inequality is crucial
for the stability of human societies; without it we would not punish
freeloaders. Dogs probably evolved this response to help them negotiate our
social world.
While the relationship between people and dogs may be built on fairness, it is
mediated through effective communication. Perhaps that is why many researchers
are fascinated by this aspect of canine cognition.
Dogs obviously do not have complex language, but they do bark. Barking is rare
among adult wild canids and feral dogs, suggesting that it evolved during
domestication to allow dogs to communicate with us, says Péter Pongrácz from
Eötvös Loránd University, Budapest.
Pongrácz and his colleagues have produced evidence that dog barks do indeed
contain information that people can understand. In 2005 they found that even
people who have never owned a dog can recognise the emotional "meaning" of barks
produced in various situations, such as when playing, left alone and confronted
by a stranger (Journal of Comparative Psychology, vol 119, p 136).
His team has now developed a computer program that can aggregate hundreds of
barks recorded in various settings and boil them down to their basic acoustic
ingredients. They found that each of the different types of bark has distinct
patterns of frequency, tonality and pulsing, and that an artificial neural
network can use these features to correctly identify a bark it has never
encountered before. This is further evidence that barking conveys information
about a dog's mental state (Animal Cognition, vol 11, p 389). They also
discovered that people can correctly identify aggregated barks as conveying
happiness, loneliness or aggression. "Even children from the age of 6 who have
never had a dog recognise these patterns," says Pongrácz.
Dogs are not just able to "speak" to us, they can also understand some aspects
of human communication. At the forum in Budapest, Akiko Takaoka from Kyoto
University in Japan described as-yet unpublished work that examined what is
going on inside a dog's mind when it hears a stranger's voice. She played dogs a
series of recordings of unfamiliar voices - both male and female - with each
voice followed by a photo of a human face on a screen. If the gender of the face
did not match that of the voice, the dogs stared longer, a sign that their
expectations had been violated.
"This suggests that dogs generate an internal visual representation of a male or
female correlated with the voice," says Takaoka. She suggests that this ability
to infer information about a person from their voice alone might help dogs
communicate with people. This is similar to what we do when we judge someone's
age, sex or mood from the way they talk in order to gain information upon which
to base our interactions.
Meanwhile, Juliane Kaminski at the University of Cambridge has been
investigating how dogs interpret other forms of human communication. Experiments
have already established that dogs can use human gestures such as pointing and
gazing to find hidden food or toys (Journal of Comparative Psychology, vol 115,
p 122). Kaminski wanted to know whether dogs simply learn to associate these
kinds of gestures with a reward, or actually understand that these gestures are
intended as a form of communication. This concept of "intentionality" is
considered to be highly sophisticated.
To find out, she adapted a test originally done with 1-year-old children. A
reward is placed under one of two containers, which are then moved around. The
experimenter then makes either a communicative gesture, pointing, gazing or
both, to indicate where the reward is, or makes a similar but non-communicative
gesture, such as checking her watch or moving her head in its general direction.
Just like babies, dogs usually choose correctly after deliberate pointing or
gazing, but did no better than pure chance when she used a non-communicative
action.
So when we point or look, dogs understand that we are trying to tell them
something. "Domestication seems to have shaped dogs in a way which enables them
to use these gestures from as early as six weeks," she says.
To what extent, though, can dogs understand referential communication such as
icons and pictures? To find out, Kaminski recruited three dogs that could
already identify dozens of toys by name and fetch them from another room on
request.
Copydogs
Kaminski wanted to know how far she could push the dogs towards using
referential communication. When the dogs were shown a replica or miniature of a
toy they returned with the correct original, showing that they understood some
forms of iconic communication. In a paper to be published in the journal
Developmental Science, she reports that one dog even managed to retrieve a toy
after seeing a picture of it.
This observed behaviour puts dogs among the elite. Other animals, including
chimps and dolphins, can be taught to do similar things, says Kaminski, but only
after intensive training. Dogs of even average intelligence can be trained to do
it more readily. Some, including the three in the experiment, learn it
spontaneously.
"Dogs identify human communicative behaviours in ways similar to human infants,"
says Jószef Topál from the Hungarian Academy of Sciences. In fact, he believes
the similarities between dogs and infants do not end there, arguing that
evolution has left dogs with a mind primed for social interactions in much the
same way as our own.
The first step in human socialisation is for a baby to become attached to its
carer, and we have known for some time that dogs attach to their owners in the
same way. For example, dogs will explore an unfamiliar room if their owner is
present, but become anxious and timid if the owner leaves - a pattern of
behaviour that is also seen with babies and their primary carers.
Topál has now moved on to the next stage of human socialisation, which involves
a specialised form of learning called pedagogy. While animals, including chimps,
learn by emulation - watching others complete a task and then using a mixture of
copying and extemporising to achieve the same result - we are uniquely capable
of exact imitation. This is the defining feature of pedagogy, and it occurs
spontaneously between infants and their carers (New Scientist, 1 April 2006, p
42).
Pedagogy begins with the teacher using eye contact, gesture and vocalisation to
direct the attention of the learner. Dogs, uniquely among animals, do the same.
"Dogs' performance matches children's," says Topál. He believes that these
attention cues trigger a receptive attitude in dogs that is comparable to
pedagogical learning in humans.
This is backed up in experiments by Ludwig Huber and colleagues at the
University of Vienna in Austria. They based their work on a classic pedagogy
experiment in which an instructor demonstrates to a toddler how to turn off a
light using her forehead. In one version of the demonstration, the instructor
has her hands clearly visible on the table. In the second version, her upper
body is wrapped in a shawl so that she can't use her hands. When invited to turn
the light off for themselves, toddlers who were shown the first version use
their heads, but those shown the second use their hands. The interpretation is
that the first group conclude that there must be a good but non-obvious reason
for using the forehead method, as otherwise the instructor would have used her
hands.
Huber has found that dogs do exactly the same thing. In an experiment where dogs
had to pull a lever to obtain a reward, the default choice was to use their
mouths. They would do this even after a demonstrator dog had used its paw - but
only if the demonstrator had a ball in its mouth. If it used its paw when it
could have pulled with its mouth, then they copied the action exactly.
Findings like these are leading some researchers to propose that dogs have at
least a rudimentary form of "theory of mind", the mental capacity that enables
us to understand the desires, motivations and intentions of others. It is
generally accepted that a few other animals, including great apes, are capable
of this mind reading to some extent, but it is nevertheless a quality reserved
for only the most intelligent of species. So that puts dogs in intellectually
elevated circles.
Alexandra Horowitz from Barnard College in New York agrees. Her own recent study
illustrates the point: when dogs play together, they use appropriate signals for
grabbing attention or signalling the desire to play depending on their
playmate's apparent level of attention, such as whether it is facing them or
side-on (Animal Cognition, DOI: 10.1007/s10071-008-0175-y). That could best be
interpreted as a rudimentary theory of mind, she says: not quite mind reading,
but more sophisticated than simply reading body language and reacting in
stereotyped ways.
We've come a long way. The study of dog psychology began with Pavlov, and even a
few years ago the notion of dogs having a theory of mind would have been
dismissed out of hand. As we delve deeper, however, the inner world of dogs is
starting to look awfully familiar. Maybe we should be the ones feeling guilty
for not realising it sooner.
From issue 2670 of New Scientist magazine, 20 August 2008, page 33-35
Wild at heart
Genetic evidence tells us that domestic dogs are descended from grey wolves,
with dogs being biologically classified as a subspecies of Canis lupus. Put a
wolf into the alien environment of a human home, though, and it becomes very
clear that domestication has taken dogs a long way from their wild roots.
The traits that we prize most in dogs are simply not there in wolves: they are
hard to train, wary of new experiences, scared of strangers and unpredictably
aggressive. They also have some rather antisocial habits. For example, they
scent-mark a lot, like to escape and would probably trash your home. On the
upside, wolves don't bark - although that probably limits their ability to
communicate with people (see main story). Instead, they howl.
Owning a pet wolf is increasingly fashionable and there are plenty of websites
offering tips to would-be wolf tamers. However, the best advice, according to
canine behaviour expert James Serpell from the University of Pennsylvania, is
don't. "Wolves do not make ideal house pets," he says. That might also help to
explain why our ancestors apparently only domesticated wolves once, despite the
two species living together over large swathes of the globe for millennia.
--
Frederick Martin McNeill
Poway, California, United States of America
mmcn...@fuzzysys.com
******************************************
"I never cease being dumbfounded by the unbelievable things people believe."
- Leo Rosten
******************************************
Immortalist
> http://environment.newscientist.com/article/mg19926700.200
> Dogs aren't stupid wolves; they are much smarter
> 20 August 2008
> NewScientist.com news service
> Kate Douglas
>
> IF YOU have ever caught a dog stealing food, you will know the feeling: a sense
> that the dog knows it has done wrong and feels... well, guilty. Maybe that's
> pushing it - but try telling a dog owner that their pet cannot experience pain,
> excitement, love or other mental states we usually reserve for humans. You won't
> get very far.
>
> Until a decade or so ago, scientists interested in animal behaviour would have
> dismissed these observations as sentimental anthropomorphising. They considered
> popular attitudes to pet dogs silly, and saw the animals themselves as little
> more than dumbed-down wolves. Above all, there was a widespread view that
> domesticated animals in general were "artificial" products of human breeding,
> irrelevant to anyone interested in studying real animal behaviour.
>
> How times have changed. Last month more than 200 experts attended the first
> Canine Science Forum in Budapest, Hungary, where they discussed, among other
> things, what is going on inside the mind of a dog. While still some way from
> painting a full picture of the canine Umwelt, their work is making it clear that
> our inclination to invest dogs with human-like states of mind isn't as
> unscientific as it might appear. Dogs really do have some remarkable mental
> skills that allow them to thrive in their strange habitat - our world.
>
- : African Wild Dog Society.
African wild dogs, unlike lions, do not attack each other. The
dominant male or dominant female (each sex has its own hierarchy),
lets his or her superiority be known by posture and tail position.
Submission is quite elaborate and ritualistic. Members of this species
seem to like being 'the underdog'-they literally burrow beneath each
other, with the whole group sometimes forming a heap. When a domestic
dog licks you, this is a similar form of ritual submission, derived
from the dog's direct ancestor, the wolf.
As hunters, African wild dogs are very successful. The pack leader
singles out a zebra or gazelle and chases it, while the others follow
in a widely dispersed line, to catch the prey even if it zig-zags.
Speed (up to 40 mph) and endurance are essential. After one dog seizes
the prey, the others help to immobilize it, and may devour it entirely
in only ten minutes. Lacking either free arms or anatomical pockets,
the dogs must carry food back to the den by eating it and then
regurgitating it. Even if the dog did not get enough to satisfy
himself, he will still apportion a share to the others. Because of
this, disabled adults at the den may be supported indefinitely. As
will be seen later, the hunting niche has caused some behavioral
similarities between canines and humans. Perhaps it is evolutionary
convergence of emotional traits that makes dogs such understanding
companions...
...Some features which humans share with African wild dogs, probably
due to their similar ecological niche as social predators, are:
eagerness to submit to leadership, willingness to share food, the male-
female long-term pair-bond, team spirit and cooperation in work, and
some communal care and training of offspring...
...Perhaps it would be more useful to look at dogs and wolves for
evidence of morality. Indeed, due to a similar ecological niche, as
social predators, dogs have independently evolved a number of traits
like us. Examples are: obedience to a leader, patience and endurance
while stalking prey, team spirit, and self-restraint. (To be fair, I
should also mention that, because of hunting, carnivores are known for
their cunning too, and their ruthlessness in attack-perhaps we share
these qualities as well.) The central issue of food-sharing in the
pack-dogs' lifestyle is probably the main cause of their developing a
conscience. They must restrain themselves not to consume more than
their share of meat. As is well known, even the domestic dog can
easily be trained not to eat meat left on the kitchen table. And a
'moralizing look' from his owner may be ample punishment for the dog
if he transgresses.
Human Evolution - A Philosophical Anthropology
-- Mary Maxwell
http://www.amazon.com/exec/obidos/tg/detail/-/0231059469/
> Domestic dogs evolved from grey wolves as recently as 10,000 years ago. Since
> then their brains have shrunk, so that a wolf-sized dog has a brain around 10
> per cent smaller than its wild ancestor (see "Wild at heart"). That was one
> reason why animal behaviourists felt dogs were merely simple-minded wolves.
From the text below "there has been a rather steep decline in the size
of the human brain during the past 15,000 years, partly but not wholly
reflecting a shrinking body that seems to have accompanied the arrival
of dense and 'civilized" human settlements...."
Hox genes are the recipes for proteins called "transcription factors,"
which means that their job is to "switch on" other genes. A
transcription factor works by attaching itself to a region of DNA
called a promoter. In creatures such as flies and people (as opposed
to bacteria, say), promoters consist of about five separate stretches
of DNA code, usually upstream of the gene itself, sometimes
downstream. Each of those sequences attracts a different transcription
factor, which in turn initiates (or blocks) the transcription of the
gene. Most genes will not be activated until several of their
promoters have caught transcription factors. Each transcription factor
is itself a product of another gene somewhere else in the genome. The
function of many genes is therefore to help switch other genes on or
off. And the susceptibility of a gene to being switched on or off
depends on the sensitivity of its promoters. If its promoters have
shifted or have changed sequence so that the transcription factors
find them more easily, the gene may be more active. Or if the change
has made the promoters attract blocking transcription factors rather
than enhancing ones, the gene may be less active.
Small changes in the promoter can therefore have subtle effects on the
expression of the gene. Perhaps promoters are more like thermostats
than switches. It is in the promoters that scientists expect to find
most evolutionary change in animals and plants-in sharp contrast to
bacteria. For example, mice have short necks and long bodies; chickens
have long necks and short bodies. If you count the vertebrae in the
neck and thorax of a chicken and a mouse, you will find that the mouse
has 7 neck and 13 thoracic vertebrae; the chicken has 14 and 7
respectively. The source of this difference lies in one of the
promoters attached to one of the hox genes, Hoxc8, a gene found in
both mice and chickens whose job is to switch on other genes that lay
down details of development. The promoter is a 200-letter paragraph of
DNA, and it has just a handful of letters different in the two
species. Indeed, changes in as few as two of these letters may be
enough to make all the difference. The effect is to delay the
expression of the Hoxc8 gene slightly in the development of the
chicken embryo. Since ; development of the vertebral column starts at
the head, this means the chicken goes on making neck vertebrae longer
than the mouse. In the python, Hoxc8 is expressed right from the head
and goes on being expressed for most of the body. So pythons consist
of one long thorax-they have ribs all down the body.
The beauty of the system is that the same gene can be reused in
different places and at different times simply by putting a set of
different promoters beside it. The "eve" gene in fruit flies, for
example, whose job is to switch on other genes during development, is
switched on at least 10 separate times during the fly's life, and it
has eight separate promoters attached to it, three upstream of the
gene and five downstream. Each of these promoters requires 10-15
proteins to attach to it to switch on expression of the eve gene. The
promoters cover thousands of letters of DNA text. In different
tissues, different promoters are used to switch on the gene. This,
incidentally, seems to be one reason for the humiliating fact that
plants usually have more genes than animals. Instead of reusing the
same gene by adding a new promoter to it, a plant reuses a gene by
duplicating the whole gene and changing the promoter in the duplicated
version. The 30,000 human genes are probably used in at least twice as
many contexts during development, thanks to batteries of promoters.
To make grand changes in the body plan of animals, there is no need to
invent new genes, just as there is no need to invent new words to
write an original novel (unless your name is Joyce). All you need to
do is switch the same ones on and off in different patterns. Suddenly,
here is a mechanism for creating large and small evolutionary changes
from small genetic differences. Merely by adjusting the sequence of a
promoter, or adding a new one, you could alter the expression of a
gene. And if that gene is itself the code for a transcription factor,
then its expression will alter the expression of other genes. Just a
tiny change in one promoter will produce a cascade of differences for
the organism. These changes might be sufficient to create a wholly new
species without changing the genes themselves at all.
In one sense, this is a bit depressing. It means that until scientists
know how to find gene promoters in the vast text of the genome, they
will not learn how the recipe of a chimpanzee differs from that of a
person. The genes themselves will tell them little, and the source of
human uniqueness will remain as mysterious as ever. But in another
sense it is also uplifting, reminding us more forcefully than ever of
a simple truth that is all too often forgotten: bodies are not made;
they grow. The genome is not a blueprint for constructing a body; it
is a recipe for baking a body. The chicken embryo is marinated for a
shorter time in the Hoxc8 sauce than the mouse embryo. This is a
metaphor I shall return to frequently in the book, for it is one of
the best ways of explaining why nature and nurture are not opposed to
each other but work together.
As the hox story illustrates, DNA promoters express themselves in the
fourth dimension: their timing is all. A chimp has a different head
from a human being not because it has a different blueprint for the
head, but because it grows the jaws for longer and the cranium for
less long than does the human being. The difference is all timing.
The process of domestication, by which the wolf was turned into the
dog, illustrates the role of promoters. In the 1960s, a geneticist
named Dmitri Belyaev was running a huge fur farm near Novosibirsk in
Siberia. He decided to try to breed tamer foxes, because however well
they had been handled and however many generations they had been kept
in captivity, foxes were nervous and shy creatures in the fur farm
(with good reason, presumably). So Belyaev started by selecting as
breeding stock the animals that allowed him closest before fleeing.
After 25 generations he did indeed have much tamer foxes, which, far
from fleeing, would approach him spontaneously. The new breed of foxes
not only behaved like dogs; they looked like dogs. Their coats were
piebald, like a collie's coat; their tails turned up at the end; the
females came on heat twice a year; their ears were floppy; their
snouts were shorter and their brains smaller than those of wild foxes.
The surprise was that merely by selecting tameness, Belyaev had
accidentally achieved all the same features that the original
domesticator of the wolf had gotten-and that was probably some race of
the wolf itself, which had bred into itself the ability not to run
away too readily from ancient humans' rubbish dumps when disturbed.
The implication is that some promoter change had occurred which
affected not one but many genes. Indeed, it is fairly obvious that in
both cases the timing of development had been altered so that the
adult animals retained many of the features and habits of pups: the
floppy ears, the short snout, the smaller skull, and the playful
behavior.
What seems to happen in these cases is that young animals do not yet
show either fear or aggression, traits that develop last during the
forward growth of the limbic system at the base of the brain. So the
most likely way for evolution to produce a friendly or tame animal is
to stop brain development prematurely. The effect is a smaller brain
and especially a smaller "area 13," a late-developing part of the
limbic system that seems to have the job of disinhibiting adult
emotional reactions such as fear and aggression. Intriguingly, such a
taming process seems to have happened naturally in bonobos since their
separation from the chimpanzee more than 2 million years ago. For its
size the bonobo not only has a small head but also is less aggressive
and retains several juvenile features into adulthood, including a
white anal tail tuft, high-pitched calls, and unusual female genitals.
Bonobos have unusually small area 13s.
So do human beings. Surprisingly, the fossil record suggests that
there has been a rather steep decline in the size of the human brain
during the past 15,000 years, partly but not wholly reflecting a
shrinking body that seems to have accompanied the arrival of dense and
'civilized" human settlements. This followed several million years of
more or less steady increases in brain size. In the Mesolithic (around
50,000 years ago) the human brain averaged 1,468 cc (in females) and
1,567 cc (in males). Today the numbers have fallen to 1,210 cc and
1,248 cc, and even allowing for some reduction in body weight, this
seems to be a steep decline. Perhaps there has been some recent taming
of the species. If so, how? Richard Wrangham believes that once human
beings became sedentary, living in permanent settlements, they could
no longer tolerate antisocial behavior and they began to banish,
imprison, or execute especially difficult individuals. In the past in
highland New Guinea, more than one in ten of all adult deaths were by
the execution of "witches" (mostly men). This might have meant killing
the more aggressive and impulsive-and hence more develop-mentally
mature and bigger-brained-people.
Such self-taming, however, seems to be a recent phenomenon in our
species and is not able to explain the selective pressures that led to
the divergence of human beings from chimp-like ancestors more than 5
million years ago.
NATURE VIA NURTURE - genes, experience, and what makes us human
http://www.amazon.com/exec/obidos/tg/detail/-/0060006781/
Don Stockbauer
enlightening us.
"Sir Frederick" <mmcn...@fuzzysys.com> wrote in message
news:d407b4thhd7o0bq1p...@4ax.com...
ZerkonX
> Dogs really do have some remarkable mental skills that allow them to
> thrive in their strange habitat - our world.
As opposed to cats who have some remarkable mental skills that allow us
to thrive in the strange habitat of their world.
Art
My cat is convinced that God created man to open closet doors for
cats.
ZerkonX
> My cat is convinced that God created man to open closet doors for cats.
Cats are also convinced that standing in front of a door waiting for
their human to open the door, then as the interrupted and owned human
does, walking away now seemingly disinterested in passing through the
door, looking back at the human as if to say, "are you really that dumb
you fell for that old gag?" as being GREAT FUN!!
Sir Frederick
An example of hubris?
Shrik...@gmail.com
> Friederike Range from the University of Vienna, Austria, takes the concept of
> dog morality even further. In a series of experiments, her team rewarded dogs
> with a food treat if they held up a paw. They found that when a lone dog was
> asked to give its paw but received no treat, it would persevere for the entire
> experiment, which lasted 30 repetitions. However, if they tested two dogs
> together but only rewarded one, the dog who missed out would make a big show of
> being denied its treat and stop cooperating after just a few rounds. "Dogs show
> a strong aversion to inequity," says Range. "I prefer not to call it a sense of
> fairness, but others might."
>
> "Dogs show an aversion to inequality. Some might call it a sense of
> fairness"This is quite a claim: even the idea that primates respond to
> unfairness in a similar way to people is highly contested. So why would a dog
> need such a trait? Range points out that the concept of inequality is crucial
> for the stability of human societies; without it we would not punish
> freeloaders. Dogs probably evolved this response to help them negotiate our
> social world.
Here's the reason I wouldn't call this behavior
indicative of "an aversion to inequality." I have
never met a dog who minded getting more than
his or her fair share. They mind being slighted,
to be sure, but I didn't see any text in the above
about the dog who was rewarded while the other
wasn't complaining about the situation. My
experience is, too, that dogs will actually seek
to get more than their comrades.
This probably evolved because "the squeaky
wheel gets the grease."