Greg Detre
Friday, June 01, 2001
Prof. Marian Dawkins
Animal Behaviour VI
Notes � animal behaviour VI, cognitive
Notes �
Dawkins, �Through our eyes only�, ch 2
Notes �
Byrne, �The thinking ape � evolutionary history of intelligence�, ch 9
Ch 7, �Tools
of deceit�, pg 155+
Notes �
Gould & Gould, �The animal mind�
Notes � web,
�Dolphins mirror tests�
Dawkins,
�Through our eyes only�
Dennett, �Do
animals have a theory of mind?�
Heyes,
�Theory of mind in non-human primates�
Dennett, �Do
Animals Have Beliefs?�
Heyes,
�Theory of mind in nonhuman primates�
What cognitive abilities do animals really have?
Do animals have a concept of number?
Do animals have a theory of mind?
Marian Dawkins, Through our eyes only
Richard Byrne, The thinking ape � evolutionary history of intelligence
Marc Hauser, Wild minds
Gould & Gould, The animal mind
Hare et al. (2000), �Do chimpanzees know what conspecifics know?�
Povinelli et al. (2000), �Towards a science of other minds: escaping the argument from analogy�
Bloom & German (2000), �Two reasons to abandon the false belief task as a test of the theory of mind�
Daniel C. Dennett, �Do Animals Have Beliefs?�, in Herbert Roitblat, ed., Comparative Approaches to Cognitive Sciences, MIT Press, 1995.
Heyes, C. M. (1998). Theory of mind in nonhuman primates. Behavioral and Brain Sciences 21 (1): 101-134.
Gallup, G. Jr (1998), �Animal Self-Awareness: A Debate � Can animals emphathise - Yes� in SciAm
Povinelli, D. J. (1998), �Animal Self-Awareness: A Debate � Can animals emphathise � Maybe not� in SciAm
Dennett (1996), Kinds of minds
Dennett, D., 1983, "Intentional Systems in Cognitive Ethology: the 'Panglossian Paradigm' Defended," Behavioral and Brain Sciences, 6, pp.343-90
Daniel C. Dennett, 1995/6???, �Cog as a Thought Experiment� for Robotics and Autonomous Systems, FINAL DRAFT for Monte Verit�ssue
Dawkins is trying to demonstrate that, consciousness aside, animals� behaviour is often a great deal more complex than we are prepared to give them credit for, and certainly not always �blind� or innate. In the case of vervet monkey grunts, we were aware that they had a set of vocal calls for different danger signals, but it emerged later that their uniform-sounding grunts are actually distinguishable into four different grunts (using a computer to look at the sound waves).
Tinbergen told the story of how his sticklebacks became very aggressive when a red postal van drove past, and Lorenz�s experiments of chicks imprinting on cardboard cut-outs are famous examples of how dumb animals can sometimes seem.
Ostriches have a bizarre practice of kidnapping each other�s chicks, forming larger and larger broods comprised mostly of others� offspring. The reason appears to be that ostrich broods make such conspicuous targets anyway, so the larger the number of chicks, the smaller the chance that a predator attack will lead to one�s own chicks being eaten. However, what�s really surprising is that ostrich mothers appear to be able to tell their own eggs apart, despite the apparent similarity between all ostrich eggs to a human eye. When incubating the eggs, ostrich mothers kick out all others� eggs, seemingly telling them apart solely on the basis of the pattern of tiny pits on the surface of the eggs.
Red deer females cluster in groups, and when it comes to the 5 or 6 week mating season, a male groups them together and guards them against other males, who either try to sneak copulations or challenge the dominant male for possession of the whole group. Because this guarding is so arduous and allows for little let-up, dominant males don�t get time to eat and get very tired, deteriorating physically over the course of the mating season. The roaring ritual that precedes a fight appears a good, i.e. unbluffable, indication of how good a fighter a deer will prove (more reliable than antlers, which don�t show the deer�s current condition).
The black grouse have evolved striking white tails against a black body, and a careful male preening display in groups (in locations called �leks�), where the females strut between them, provoking fights. The females choose the males, partly it seems on the basis of their white tails, but also on quite undetectable but non-random grounds. The Swedish team (H�nd) eventually realised that the females were choosing the mates that would survive over the course of the next 6 months very accurately, but none of the team�s measurements, of tail size, position in lek, number of parasites, size etc. proved a good predictor.
Hens have a strict pecking order that is established with great violence when first put in a group together, and observed more or less without incident thereafter.
Bruce Falls looked at the territorial behaviour of white-throated sparrows. They sing, as a means of warning other approaching males of their territorial boundaries, which is a cheaper means of alerting them than squaring off every time. Each individual sings a variation of the species song, with slightly different pitch. The birds learn to ignore their immediate neighbours� songs, since they have established their own respective territories, and only take up the challenge of a stranger�s song. Interestingly though, if a �safe� neighbour�s song is replayed from a different side of the territory, the male responds as if to a stranger, indicating that they are aware of their neighbours� relative positions.
Sherry, Shettleworth and Krebs compared chickadees (North American) with marsh-tits (European), and showed that both species seem to be were able to remember hundreds of different positions where they have stored food. The experimenters used a cluster of artificial trees with velcro doors, behind which the birds could store peanuts, which the experimenters then moved, opening and closing doors. After 24 hours, the birds appeared to be searching systematically in the places where they had stored the food, without employing any cues except location.
discussion of rats � see social learning
Dawkins now wants to show that animals appear to be making decisions, co-operating and evaluating the trustworthiness of other animals.
Elgar showed that sparrows sighting food make a set of decisions about whether or not to chirrup to recruit fellow sparrows. If there is enough food, it�s sharable, the sparrow is not desperately hungry, and the danger or possibility of a predator is high, then he is likely to chirrup rapidly to attract many other sparrows, all of whom fly down to the food together, so that there is more likely to be one sparrow looking up at any one time to see if a predator is coming. This complexity of decision-making need not necessarily imply consciousness.
Vampire bats are very social creatures. They feed by making a 3mm incision in a larger mammal (e.g. cows, horses, donkeys), and for 15 minutes lap up <40% of their own body weight in blood (their saliva stops the hole clotting), although this is an insignficant amount for the mammal. They live together in roosts, chosen for warmth and dryness. If a bat does not find an animal to feed on every so often (every 8 days???), it will starve. The likelihood of a bat�s finding food is pretty much down to chance, and no one bat is much better than another. If another successful bat sees a hungry bat, it will regurgitate (i.e. donate) some of the blood it has found. But the bats show preferential treatment to relatives (mothers and daughters), and bats they have swapped with in the past. Not all bats in the colony get this preferential treatment, and not strange bats. Wilkison studied vampire bat colonies, and established a captive colony. He noticed that the closest feeding bonds tended to be between two or more females, usually roost mates (those who roost next to each other). There are many and frequent opportunities for reciprocation, and the starving bat gains far more utility from the donated blood than the donator would have.
Vampire bats show a much higher level of social co-operation than horses whisking flies off each other�s noses and oxpecker birds eating the ticks off a rhinoceros. A cheating sparrow (that never looked up while feeding in a group) might get away with it, but a cheating vampire bat would be remembered by those it had encountered previously and would not be given food.
taking another�s
visual perpective doesn�t tell you what they know, only what they see
The great apes definitely do have a theory of mind. This is an evolved ability, which they can now apply to various situations that are very different to what originally favoured the evolution of the underlying copmetence.
It can be extremely difficult to assess whether an animal possesses a theory of mind, or whether it is merely following a �blind�, i.e. genetically hard-wired, series of actions which has the result of causing one or more other animals to behave in a way that benefits the agent. The best way to classify �theory of mindedness� is using Dennett�s levels of �intentionality�.
intentionality in the philosophical sense, of �aboutness� � see Stanford entry, on ethologists� confusions with consciousness
The kind of innate behaviour that has evolved to exploit other animals without the agent�s having formed any conception of why the action is beneficial for them is known as zero-order intentionality. The eyed hawk-moth is a good example. The markings on its wings, when spread, look like a pair of hawk eyes staring at the on-looking animal. The hawk-moth �knows� that when it spreads its wings at small mammals, on whom the hawk predates, they will probably mistake it for a hawk and flee. However, there appears to be no intentionality exhibited � the hawk-moth is not representing the mind and behaviour of the small mammals in its brain, and predicting their behaviour on the basis of this neural representation. This can be seen in that it uses the same trick when faced with cardboard props and actual hawks, despite the inappropriateness of the action.
zero-order
intentionality need not necessarily be genetically hardwired though
First-order intentionality allows that the animal is able to predict the consequences of its action
It is worth noting that when ethologists talk of �deceit� in animal communication, they may mean either of these senses � the speech marks around �deceit� highlight the lack of intentionality behind the action, in order to differentiate this technical use of the term from human deceit.
In order for an animal to be considered to possess a theory of mind, it must demonstrate second-order intentionality.
dolphin theory of mind stuff
theory of mind��������������������������� 163, 227, 251-52
animal experiments����������� 165-72, 250, 252
animal vocalisations���������� 195
language�������������������������������� 171-72
Tells the joke: �Don�t touch, The Strongest Man in the World�, trumped by �Thanks for the beer, The Fastest Man in the World�.
Humour demonstrates our surprise when events overturn our beliefs. Cheney and Seyfarth used an expectancy-violation procedure to show that wild baboons (in the Okavango Delta of Botswana) could detect an anomaly in the natural sequence of events. Usually, a dominant female will grunt, to which a subordinate will bark back. When they played a subordinate�s grunt followed by a dominant�s bark, they expected and found that baboons would look longer after the playbacks, suggesting that baboons form expectations based on the meaning of the call, the identity of the caller and the dominance relationship. This technique can be used to detect violations of the current state of affairs, mismatches tewen signal and context.
At Cheney and Seyfarth�s vervet monkey site in Kenya, Hauser noticed Tristan (the alpha male) trying unsuccessfully to copulate with Borgia (the alpha female). When he slapped Borgia, she screamed, and all her female relatives chased after Tristan. Suddenly, Tristan stopped, and gave a loud leopard alarm call, and just stood there as they all fled into the trees. There was no sign of any predator. This appeared to be deception, active falsification of information about the presence of a predator. But the 2000 hours over two years of observation never yielded another such example. It could have been a mistake, or it could have been an outright lie. Hauser doesn�t say whether Tristan�s reputation was damaged. White and Byrne termed this �tactical deception�, in that it�s not stereotyped, innate or species-wide trick, nor is it common or repeated often over a long period. Tristan�s use of the call in such a context seems very rare.
De Waal detailed how an captive adolescent female chimpanzee, Oor, used to scream when climaxing, even during clandestine mating sessions. By adulthood, she screamed when copulating with the alpha male, but screamed noiselessly with all other males. Whiten and Byrne collected 253 such reports in a database. For some taxonomic groups, like the prosimians (e.g. lemurs, sifakas, indris) and lesser apes (e.g. gibbons, siamangs), virtually no cases have been reported. On the other hand, wild and captive great apes (orangutans, gorillas, chimpanzees and bonobos) have many cases.
If you were a bird sitting on your eggs, and saw a cat wandering nearby, what would you do? You could hope the cat doesn�t see you (and many birds camouflage their nests carefully), you could attack the cat, but you can�t fly away and leave your eggs, and you can�t move your nest and/or eggs. The plover, which nests on the ground, has developed a technique of flying out into the open, flapping about, diving downwards, then feigning an incapacitated wing injury to distract the predator�s attention, before flying off and hoping that the cat has forgotten about the nest.
Carolyn Ristau used humans as predators, and noticed that the plovers were sensitive to where the predator was looking, and the path travelled. But does this discrimination between safe and dangerous intruders demonstrate goal-directed behaviour, guided by an awareness of their own beliefs, the beliefs of others, and how they can be manipulated?
mirror-image recognition��������� 156-159
Premack, David�������������������������� 175-176, 184-186, 188-190
language,
human/primate�������������������� 194
word-order���������������������������� 180-188, 206-208
trial and errror learning������������ 49-53, 167, 79-81, 65-66, 83
sympathy�������������������������������������� 150
Pepperberg, Irene���������������������� 178-180
Vervets pay less attention to alarm calls given by infants, and learn to ignore any cry from an individual who has �cried wolf� after about 8 playback repetitions, although they pay attention to the same cry played back of a different individual.
�chutter� = all group together, approaching monkeys
�wrr� = less serious, approaching monkeys
alternative essay title: why do animals have a theory of mind?
of course, humans show higher-order intentionality, in that we can talk about talking about second-order intentionality. But it�s pretty easy to tell with humans, not least of all because they can use language to demonstrate their beliefs and intentions.
triadic, social
size of social groups
question of theory of mind in animals is related to theory of mind in human infants, and mentally handicapped children
Premack & Woodruff�s (1978) question, �Does the chimpanzee have a theory of mind�
status of the false belief task
show how the possible ways of assessing match up with the type of experiments that have been performed
chimps pass a simple false belief test with two humans pointing to different cups (Povinelli)
is there a way that I can use discussions of whether animals have beliefs as part of the discussion of theory of mind???
what role does the false belief task play in theory of mind???
can we see any link between theory of mind, and consciousness???
is there a correlation between higher-order thoughts, intentionality and theory of mind???
how do monkeys respond to (the approach of) monkeys of other species???
do insects have bones and skeletons??? if not, is that why they are called invertebrates???
what was the second reason for discarding the false belief test in Bloom & German???
chimps are great apes, which are different to monkeys, right???
what is the difference between theory of mind and a complicated algorithm that takes the states of other agents into account as parameters???
if you have a theory of mind, aren�t you necessarily cognitivist???
why do red deer guard such big groups alone, rather than guarding and attacking in small groups (like lions???)???
is it possible that the females� choice of black grouse mate in some way influenced which males would survive (i.e. the ones that weren�t picked lost the will to live in some way, or something)???
is feeding on blood (e.g. vampire bats) common??? is it efficient???
how do the vampire bats tell that another bat is hungry??? is this not deceivable??? do they bats count the number of interactions, i.e. who owes whom how often, or do they simply remember reliability???
does Dennett really think that if something can be captured within the intentional stance that it has a �belief�???
well, I suppose it does, insofar as it has a representation of the environment �xxx???
what does Davidson (1975) mean when he talks about meta-linguistic concepts of truth and falsehood as necessary for belief???
must there be plasticity in order for there to be beliefs (�There has to be structure; there have to be elements of plasticity that can go into different states and thereby secure one revision or another of the contents of the agent's beliefs�)???
under Dennett�s intentional stance criterion, Deep Blue would have a set of beliefs about a chess-board, wouldn�t it??? how is that different/related to the robot with the map in its head who can�t tell that J, K and L lie on a straight line???
matched dependent behaviour, e.g. chimps imitating novel gestures???
emulation learning???
is imitation a good test??? after all, in order for animal to imitate another animal or a human, it must be kind of acknowledging that the demonstrator is an agent of some kind, right??? you don�t see chimps imitating trees, do you??? but isn�t there more to theory of mind than just acknowledging other animals� agenthood??? what???
anaesthetic artefact hypothesis in mirror tests???
have they tried any self-recognition tests with camera/TV set-ups???
are there individuals that have been born with blindsight, and do they develop �guessing strategies� to behave almost normally??? would their visual system develop at all??? does anyone have complete blindsight??? from birth??? is Povinelli right in thinking that their only difficult would be in understanding other people�s visual experiences???
if that were true, they would find it more difficult to �guess� when drivers shine headlights into their eyes, and so would have some idea of the effect on seeing people�
how closely do I think theory of mind and self-consciousness are related??? do I need one in order to have the other???
what does the mirror test test??? what other tests are there besides the mirror test??? are there other types of mirror test???
is theory of mind/self-consciousness on-or-off, or does it admit degrees???
which animals pass which tests??? is there a checklist???
is theory of mind related more to social interaction than complexity, hands, language or self-consciousness???
is the fact that the hawk-moth tries the same wing-spreading trick on cardboard props and actual hawks (what exactly does it try it on???) really evidence that it isn�t using an internal model of the onlooking animal
this is only true if it can be shown that it is able to distinguish the cardboard + hawks from small mammals, and that it has learned the behaviour�
does theory of mind have to be learned???
I suppose one could have a genetically-programmed internal model of how other conspecifics behave�
what�s the exact difference between zero- and first-order intentionality???
is the plover�s behaviour innate???
haven�t the cats got wise to the plovers yet???
is vampire bats� behaviour towards each other first-order intentionality???
�� if you succeeded in making a successful purchaser-robot, you would ipso
facto have made a robot believer, a robot desirer, because belief and
desire, in this maximally bland (but maximally useful!) sense is a logical
requirement of purchasing behavior� Others do not approve of this way with
words. Donald Davidson (1975), for instance, has claimed that only creatures
with the concepts of truth and falsehood can properly be said to have beliefs,
and since these are meta-linguistic concepts (I am simplifying his argument
somewhat), only language-using animals such as human beings can have beliefs.
A thermostat, McCarthy and I claim, is one of the simplest, most
rudimentary, least interesting systems that should be included in the class of
believers--the class of intentional systems, to use my term. Why? Because it
has a rudimentary goal or desire (which is set, dictatorially, by the
thermostat's owner, of course), which it acts on appropriately whenever it
believes (thanks to a sensor of one sort or another) that its desire is
unfulfilled. Of course you don't have to describe a thermostat in these
terms. You can describe it in mechanical terms, or even molecular terms. But
what is theoretically interesting is that if you want to describe the
set of all thermostats (cf. the set of all purchasers) you have to rise to this
intentional level. Any particular purchaser can also be described at the
molecular level, but what purchasers--or thermostats--all have in common is a
systemic property that is captured only at a level that invokes
belief-talk and desire-talk (or their less colorful but equally intentional
alternatives: semantic-information-talk and goal-registration-talk, for
instance).
I have defended a maximally permissive understanding of the term,
having essentially no specific implications about the format or structure of
the information-structures in the animals' brains, but simply presupposing that
whatever the structure is, it is sufficient to permit the sort of intelligent
choice of behavior that is well-predicted from the intentional stance. So yes,
animals have beliefs. Even amoebas--like thermostats--have beliefs. Now we can
ask the next question: what structural and processing differences make
different animals capable of having more sophisticated beliefs? We find that
there are many, many differences, almost all of them theoretically interesting,
but none of them, in my opinion, marking a well-motivated chasm between the
mere mindless behavers and the genuine rational agents.
Primatologists and other
investigators of animal behavior use a variety of substitutes for the term
"theory of mind," asking whether animals are capable of, for example,
"Machiavellian intelligence" (Byrne & Whiten 1988; Whiten &
Byrne 1988), "metarepresentation" (Whiten & Byrne 1991),
"metacognition" (Povinelli 1993), "mind reading" (Krebs
& Dawkins 1984; Whiten 1991), "mental state attribution" (Cheney
& Seyfarth 1990a; 1990b; 1992) and "pan- or pongo-morphism"
(Povinelli 1995).
I assume that individuals
have a theory of mind if they have mental state concepts such as "believe",
"know", "want" and "see", and that individuals
with such concepts use them to predict and explain behavior. Thus, an animal
with a theory of mind believes that mental states play a causal role in
generating behavior and infers the presence of mental states in others by
observing their appearance and behavior under various circumstances. However,
they do not identify mental states with behavior. For example, if chimpanzee Al
has a theory of mind, he may judge chimpanzee Bert to be able to "see"
a predator because it is daylight, Bert's eyes are open, and there is an
uninterrupted line between Bert's eyes and the predator. But Al does not take
seeing the predator to consist of these observable conditions. It is a further
fact about Bert, inferred from these conditions, which explains why Bert runs
away.
Many anecdotal reports of
deceptive behavior invite several alternative interpretations: that the
behavior occurred (1) by chance, (2) as a result of associative learning, or
(3) as a product of inferences about observable features of the situation
rather than mental states (Heyes 1993; Kummer et al. 1990; Premack 1988). For
example, "One of the female baboons at Gilgil grew particularly fond of
meat, although the males do most of the hunting. A male, one who does not
willingly share, caught an antelope. The female edged up to him and groomed him
until he lolled back under her attentions. She then snatched the antelope
carcass and ran" (observation by Strum, cited as personal communication in
Jolly 1985).� The female baboon may have
intended to deceive the male about her intentions, but it may also have been no
more than a coincidence that she began grooming the male when he was holding
the carcass, and made a grab for the carcass when he was lolling back. Even if
it did not occur by chance, the female's behavior may have been acquired
through associative learning. For example, she may have snatched the carcass
when the male was lolling back because in the past similar acts had proved
rewarding when executed in relation to supine individuals. That is, the female
could have snatched food from conspecifics on many previous occasions,
initially without regard to their posture, but if she got away with it when the
victim was supine, and not when the victim was upright, she could have acquired
an association between snatching food and reward that was activated by the
sight of a supine animal. Even if observational studies of deceptive behavior
could show that it was acquired through an inferential process rather than associative
learning there would remain the possibility that the behavior was based on
reasoning about observable features of the situation, or nonmental categories,
rather than mental state concepts. Thus, the female baboon may have inferred
from her experience of conspecific behavior that it is relatively safe to
snatch food when the other animal is lying back, but she need not have regarded
posture as an indicator of mental state.
In each of these six
sections, two questions are addressed: (1) Competence - Is there reliable
evidence that primates have the relevant behavioral capacity? (2) Validity - If
present, would this behavioral capacity indicate theory of mind? For example,
in the case of self-recognition, the competence question will be answered affirmatively
if there is clear evidence that some primates are capable of using a mirror as
a source of information about their bodies, and the evidence will be considered
clear if there is no other at least equally plausible explanation for published
observations of mirror-related behavior in primates. Similarly, the validity
question will be answered affirmatively if there is no equally plausible
nonmentalistic alternative to the hypothesis that mirror-guided body inspection
requires or involves a self-concept. More generally, the competence question
attempts to establish which environmental cues primates use to guide their
behavior, and the validity question enquires about the psychological processes
that lead them to use these cues rather than others.
It claims that mental states
such as wanting and believing control behavior, and that knowledge of such
states, mental state concepts, is used in social interaction. In contrast,
alternatives to the theory of mind hypothesis postulate just one layer of
processes or representations which generate behavior in social contexts and
elsewhere.
I maintain that knowledge of
mental states in others presupposes knowledge of mental states in oneself and,
therefore, that knowledge of self paves the way for an inferential knowledge of
others.
Species that fail to
recognize themselves in mirrors should fail to use introspectively based social
strategies such as sympathy, empathy, attribution, intentional deception,
grudging, gratitude, pretense, role playing or sorrow.
Dorothy L. Cheney and Robert M. Seyfarth of the University of Pennsylvania have found that vervet
monkeys give alarm calls on seeing a predator even if other monkeys have
already seen it, too. Likewise, they found that Japanese monkey mothers do not
distinguish between offspring that know or do not know about food or danger
when it comes to alerting their babies to the presence of one or the other.
Initial experiments by Daniel
J. Povinelli and Sarah T. Boysen of Ohio State University showed that chimpanzees
appear to distinguish between what humans may or may not know. When two humans
pointed toward different cups, the chimpanzees learned to pick the cup
implicated by the human who had witnessed which cup had been baited with food.
There are some explanations
for the negative results, however. Povinelli's experiments relied on
chimpanzees that might have been too young; the onset of self-recognition in
chimpanzees does not occur until adolescence. Still another possibility is that
we humans categorize our experiences (for example, by sight, hearing or smell).
Lacking language, chimpanzees may not distinguish between visual, auditory and
tactile experiences. Therefore, inferences they make about attention may be
more global.
Because chimpanzees and
orangutans pass the mirror test, Povinelli hypothesizes that they possess a
motor self-concept rather than a psychological one. That is, they do not really
recognize themselves but simply learn an equivalence between their behavior and
what they see in the mirror.
But matters of appearance
have little to do with movement. So why should chimps and orangutans seem so
intent on using mirrors to look at and inspect parts of their bodies they have
never seen before? Why should they bother to respond to strange but motorically
inconsequential red marks on their own faces? Suzanne Calhoun and Robert
Thompson of Hunter College describe the reaction of a
chimpanzee that, on being reintroduced to a mirror a year after learning to
recognize herself, became very agitated when she opened her mouth and saw
several missing teeth. It is hard to see how this reaction could be understood
purely in motor terms.
Compared with other great
apes, gorilla brains are the least anatomically lateralized. The absence of a
highly specialized right hemisphere might explain the gorilla's weak and
inconsistent performance in the mirror tests
Ironically, this may be close
to what Gallup himself had in mind when he originally published his discovery
nearly 30 years ago. He noted that self-recognition appears to require the
ability to project "kinesthetic feedback onto the reflected visual image
so as to coordinate the appropriate visually guided movements via the
mirror."
Adaptive use of a theory of mind
parsimony �
Premack & Woodruff (1978) suggested that "The ape could only be a mentalist.. he is not intelligent enough to be a behaviorist".
By far the most obvious candidates are our fellow higher primates.
Conclusion
if it has language, and the language demonstrates belief and theory of mind (which it surely must/does in all known cases???), then the animal has theory of mind??? even by Fodor�s standards???
download dennett article listed in Cognitive Ethology bibliography, and in Byrne ch 9
have a look in Kinds of Minds
go to RSL to pick up books
find out about dolphin theory of mind stuff, and Alex the Parrot