Do Elephants, Chimpanzees, and
Dolphins Think?
(Reflections on an Unfortunate
Paradigm Shift in
Ethology)
A Talk Given at the 30th
International Ethological Conference, August 18, 2007, Halifax, Nova Scotia,
Canada
Moti & Donna
Nissani
Department of
Interdisciplinary Studies, Wayne State University, Michigan,
USA
Contact us:
aa1674@wayne.edu
Some of the articles—and many photos of
chimpanzees, elephants, and dolphins—can be found in: www.is.wayne.edu/mnissani/
Abstract: A common tripartite classification of
the roots of animal behavior traces a particular behavior directly to one’s
genes, to equally mindless trial-and-error learning, or to thinking. Extant experimental lines of attack on
the problem of demarcating thoughtful actions from other types of actions are
briefly reviewed, paying special attention to widespread verificationist
approaches and to the nearly-forgotten Fabre’s and Thorndike’s falsificationist
methodologies. We
then review some of our own experimental applications of the falsificationist
approach to elephants, chimpanzees, and bottlenose dolphins. We propose similar, concrete,
applications of falsificationist experimental designs to claims of thinking in
corvids, apes, and other animals.
As long as we fail to apply falsificationist methodologies, Fabre’s claim
that we all too often try to “exalt animals” instead of objectively studying
them will remain as relevant today as it had been over a century ago. Finally, even if all non-human animals
lack consciousness, self-awareness, theory of mind, and thinking, we argue that
ecology, aesthetics, ethics, kinship, human borderline consciousness, and limits
to what science can know all suggest that animals deserve a far more prominent
place in our moral compass than they enjoy now.
The questions we wish to
ask: Can animals of some species
think? Solve problems in their
head? (not just blindly try everything?)
Have a concept of self? Are
animals conscious?
These are probably interrelated
aspects of the same underlying neural circuitry, but here we shall just focus on
one aspect of this complex equation:
thinking. We’ll make use of
Marian Dawkins’ reflections (1993,
Through Our Eyes Only, p. 97):
A possible definition of what we mean by thinking is not
only having internal representation of the world but that it should be able to
perform some sort of internal manipulation of that representation—working out
what would happen if one element were changed, for instance—and behaving
appropriately according to its changed presentation. Thinking is therefore most likely to
occur in animals where working out in advance what the best course of action
might be is a great deal quicker and safer than trying each one in turn and
seeing which one is best in practice.
If all an animal can do is to follow a set of rules, then there is no
reason to suspect it has a mind—that it can “think.”
Two misconceptions must be first
be dealt with:
Misconception
#1: Thinking
confers great evolutionary advantage by allowing an animal to read other minds
and solve problems in one’s own mind without trying everything through blind
trial and error. But these
advantages are perhaps more than counterbalanced by:
a.
The most successful species,
e.g., E. coli, fruit flies, probably do not think.
b.
The brain is expensive to
develop and maintain (cf., for example, Paul R. Manger, 2006,
Biol. Rev., 81:
293–338). These costs alone might outweigh any
potential benefit.
c.
Thinking often involves an
appreciation for complexity and uncertainty, and hence may lead to fumbling and
hesitation in critical situations (that is one reason why organizations like the
Iranian Revolutionary Guards and the U.S. Marines work so hard to eradicate
thinking).
d.
The only species that is
demonstrably capable of thinking and consciousness is very young (<2 millions
years?). Going by this one
exemplar, it would appear that the kind of thinking that evolution seems capable
of producing (feeble, intermittent, conformist, self-centered, narrow in scope)
could well be a recipe for extinction.
Misconception
#2: Animals deserve our love, our
compassion, our moral consideration, only if they think. We emphatically reject this narrow
view. We cannot take this issue up
here, and instead we’ll merely support our objections with one quotation
(R. D. Rosen, 2007, A Buffalo in the House, p.
200):
He had been
around a long time and he hadn’t met
many men who could understand the great but fragile web we were all part
of and wanted to help keep it together.
What Roger felt was that there had to be a better America than this
one. And maybe it was that hope
that helped explain his love for the crippled beast, this symbolic survivor of
nineteenth-century America, in the back of his horse trailer. It was animals who kept men honest. No amount of money or flattery—or even
carrots—could get an animal to be untrue to itself. The ground on which humans, which were
part animal, met animals, more human than we know, was sacred. Animals taught us to love even when we
couldn’t know whether we are loved back.
It was there, in an animal’s heartbeat, that we could feel the pulse of
something bigger than we were.
There, on that ground, we could feel the pulse of something bigger than
we were. There, on that ground, we
could feel that we were a part of nature, not apart from it. Roger flashed on the situation in
Yellowstone again. He knew that a
man who didn’t treat an animal with respect not only had no respect for nature;
he had no respect for himself.
The little-recognized Henri
Fabre (a working class Frenchman with too many principles and too few
connections, but nonetheless, in a fairer world, a serious contender to the
title of “father of ethology”, e.g., <1915, The Hunting Wasps. Read Fabre’s works, then read Lorenz’s, and judge for yourself!)
provided beautiful, solid, numerous observational refutations of the then
near-universal belief that insects think.
In one case, Fabre concluded “to understand that she [digger wasp] can
take a leg instead of an antenna is utterly beyond her powers.” The actions of insects.
are like a
series of echoes each awakening the next in a settled order, which allows none
to sound until the previous one has sounded. What a gulf separate intelligence and
instinct!
A few decades later, a
similarly powerful inference about the lack of the “power of rationality” in
animals emerged from E. L. Thorndike’s (1911, Animal Intelligence)
observations on chicks, cats, and dogs. For instance, cats learn to escape from
a puzzle box gradually, suggesting a stamping in of the association between the
stimulus and successful response, not causal reasoning. On the whole, Thorndike’s general
conclusions about the mentality of chicks, cats, and dogs seem to have stood the
test of time. For instance, in a
recent study, dogs learned to pull on a string to obtain food, but they did not
seem to understand the means-end connections of string-pulling tasks (Osthaus,
Lea, & Slater, 2004, Animal Cognition, 8:37-47). Thorndike said:
Most of the books [on animal psychology]
do not give us a psychology, but rather a eulogy of animals. They have all been about animal
intelligence, never about animal stupidity.” Human are eager to find
intelligence in animals.
Our plea is twofold:
1. We need,
indeed, to allow publication of a catalog of animal stupidities. Ethologists, and the scientific
community as a whole, should have in mind both seemingly intelligent—and
seemingly unintelligent—exemplars before deciding the issue of animal cognition.
We can find such examples
everywhere, once we start looking for them.
2. Before attributing intelligence to a particular
behavior, we must try harder to rule out the possibility that this behavior is
solely traceable to genetics, trial-and-error learning, and the interaction
between them (this is a variation of Morgan’s rule: the point here not to automatically take
a minimalist approach, but to try to experimentally disprove thinking).
àWe shall give a few examples of this latter approach in the rest of this presentation.
String-pulling in ravens and
elephants
We have done this with elephants (Nissani, 2004,
in: Comparative Vertebrate Cognition. Rogers, LJ, Kaplan G, editors,
pp 227-261), using a bungee cord.
Like the ravens, elephants have mastered the task well: video. At this point, we (and everyone else
that saw this) felt that we have proven that elephants are capable of insightful
behavior.
We then applied Fabre’s approach. In one case, we have tied the end of the
cord to a post (instead of placing it on the ground). Conceptually, the two tasks are
identical. But with this minor
discrepancy in the setup, our insightful elephants suddenly turned into a
fumbling elephant! We concluded that in the elephant’s
case—and perhaps also (an experiment worth doing!) in Heinrich’s more famous
case involving ravens—no insight was involved (Video)
Wanda, formerly of the Detroit Zoo,
readily mastered the string-pulling task (through a coordinated action of trunk
and foot or trunk and mouth)—until the string was tied to a
post.
àHere is a testable prediction: Heinrich's ravens, like our elephants, will NOT pass a similar
transfer task (and if so, their string-pulling is not
insightful)
Do animals know
that people see?
We applied Povinelli’s ingenious falsficationist
paradigm to 6 chimpanzees and some 20+ elephants, with numerous variations and
rigorous controls. We faced a
methodological problem involving the poor visual acuity of elephants. Most likely though, we find that Povinelli’s claim of 50% rate is almost certainly mistaken
in some of his own variations, and that in both species, in some tasks,
performance is roughly at the 70% level.
This is statistically significant but, in our view, Povinelli’s main
conclusion still stands (Nissani, 2004, in: Comparative Vertebrate
Cognition. Rogers, LJ, Kaplan G, editors, pp 227-261). The data are most consistent with an
acquired trial-and-error preference to interact with a human who faces you as
opposed to a human who doesn’t. One
has to see a chimpanzee, or an elephant, hesitating, looking intently at a
person who has her head covered with a bucket and a person with a bucket on her
shoulder, and then begging from the person who cannot see them, to come around
to this view. (That was the point
when one of us changed his mind about animal cognition, seeing our brightest
chimpanzee doing this). (Video)
Do
elephants know that people see? In
the buckets task, our chimpanzees performed at chance level, while elephants
chose the seeing person in 58%-78% of the cases. In this trial, the elephant is begging
from the person who could not see her.
Lifting a lid off a bucket and retrieving a
reward
Our next example comes from the simple maneuver of
lifting a lid off a bucket to get a reward inside the bucket. Now, an elephant can be taught to do
this well in some 30-60 minutes. It
looks like this: video
But what happens if you now place the treat inside the
bucket, as before, and the lid alongside the bucket, on the ground? Will the elephant behave as Fabre’s
digging wasps and pine moths? It
sure does (Nissani, 2006, J .Exp Psych: Anim Behav Proc, 31:91-96): video
After an elephant learned to lift a lid
to retrieve food from a bucket, the lid was placed alongside the bucket while
the food was simultaneously placed inside the bucket. All elephants continued to toss the lid
before retrieving the reward, raising the possibility that they have no
understanding of this simple causal relationship
The above experiments: String-pulling paradigm with variations,
Povinelli’s paradigm with variations, and lid-lifting paradigm with variations,
led us to suspect that chimpanzees and elephants do not
think.
The “throw the net” signal of the dolphins of
Laguna
We are now in the process of studying another candidate
for thinking in the animal kingdom: the bottlenose dolphin. To do this, we reluctantly let go of the
experimental option and conducted preliminary observations of a striking (and
beautiful) behavioral sequence: the
human-dolphin fishing cooperative in Laguna, Santa Catarina, Brazil (Pryor et
al., Marine
Mammal Science 6:77–82; Simões-Lopes, 1991, Biotemas, 4: 83-94).
A Dolphin in Regular Motion | A Dolphin Asking for a Net |
The Signal and subsequent dive
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As can be seen in the following video, the dolphins of
the Southern coast of Brazil herd fish towards a line of throw-net
fishermen. At a certain point, the
dolphin signals to the fishermen to cast their net. To my knowledge, the signal is unique,
not seen elsewhere in the behavioral repertoire of this animal.
A detailed motion analysis suggests that the signal is
short (mean time that any body part is seen above water while signaling: =1.4
seconds) and fairly uniform across individuals. (videos).
Our question, as before: Do the dolphins understand what they are
doing or was the behavior acquired through mindless trial-and-error
learning? We have here,
undoubtedly, a culture, if we accept Whitehead and Rendell’s definition of
culture, but to us, the critical question is not the existence of culture in
this limited sense. Rather, it
is: Is this a mindless or a
thinking culture? We hope to
provide a more definite answer to this question when we finish analyzing our
extensive video collection.
In this presentation, we’ve tried to contrast two ways
of seeing the world, two paradigms, which, in their turn, create strikingly
different ways of looking at our animal companions on this planet, something
like the famous Young Lady and the Hag.
An
illustration of a Gestalt shift (A=hag; B=young lady; C=young lady and the
hag)
These contrasting paradigms are not mere semantic
quibbles, but they entail profound effects on our way of practicing
ethology. Here we shall only
provide four illustrations of these effects:
Training of animals: The two
models—thinking vs. trial-and-error—lead to radically different training
regimes. (We may note in passing
that all animal trainers we know operate as if the trial-and-error model is the
correct one).
Animal “cultures”: Culture claims include Japanese macaques, bottlenose
dolphins (Shark Bait sponges, signal to fishermen in Laguna), Whitehead’s sperm
whales, chimpanzees nut cracking, and others. The transmission of behavioral patterns
across generations is undeniable, but, if only trial-and-error learning
underlies this, if it is mindless, it is perhaps unwise to talk about “culture”
in such cases. At least until the
issue is resolved, we should let go of the word “culture” and talk instead about
something like “social learning.”
The ongoing debate on whether primates are cognitively
special. There is a growing body of experimental
evidence from cetaceans, elephants, dogs, corvids, parrots—perhaps even geese,
fish, bees, and ants—that they too deserve a place in the rising cognitive
sun. Again, the two paradigms lead
to radically new ways of interpreting such claims. According to the thinking paradigm,
these animals are the cognitive equivalent of primates; that is, parrots may be
as smart as chimpanzees. According
to the trial-and-error paradigm, the claim of equality still holds, but for
different reasons: If no animal
thinks, then all animals are equally (un)intelligent.
Limited expression of new behavioral
traits. The coordinator of my workshop, Dr.
Zhanna Reznikova, has just
noted that culture and social learning are often restricted to a few members of
a population, e.g., not all members of the snow monkey population wash or salt
potatoes, not all bottlenose dolphins in Shark Bay use sponges; not all
bottlenose dolphins in Laguna cooperate with fishermen. Such observations are scarcely
reconcilable with the thinking hypothesis, but they are implied by the
non-thinking hypothesis.
Everyday Encounters: e.g., an eating dog attacking its scratching paw
(video); the familiar scene of a dog on a leash wrapped around a tree and unable
to extricate itself; chimpanzees losing their hands in the wild because they are
unable to figure out an exceedingly simple trap mechanism. For cognitive ethologists and lay
people, these are disturbing puzzles.
By contrast, the non-thinking camp expects blind genes and mindless
learning to produce at times such behavioral cul-de-sacs.
In our view, the question of
animal intelligence is an open one.
Science is not religion, and we should not adopt a particular viewpoint
simply because we find it agreeable or intuitively compelling. To find out whether a construct like
“cognitive ethology” is valid in the real world, we should refrain from exalting
and eulogizing animals, from directing all our energies to one side of this
question, from resenting the view and blocking the publications of those who
remind us that the animals may not think.
the moment, ethology needs a more cautious attitude to the question of
animal intelligence, and it needs to develop a catalog of animal
stupidities. Whenever possible,
ethologists need to apply Fabre’s falsificationist approach to any given situation, before
attributing thinking, insight, theory of mind, or culture to animals.
Conclusions:
1.
After
millennia of interactions with animals, we do not have a single, clearcut
example of thinking or understanding in animals. This by itself should give pause to the
cognitive ethology avalanche.
2.
The
larger brain of some animals serves many useful functions, e.g., improved
learning ability, but not necessarily thinking or understanding. There is, nowhere, neurological evidence
that animals think.
3.
The
founder of ethology, a great observer and a brilliant experimenter, and still
the greatest ethologist of them all, J. Henri Fabre,
is, at times, not even mentioned in animal behavior textbooks. Possible reasons: A Frenchman (the contemporary world of
science is dominated by the politically ascendant English-speakers), low-class
origins (likewise, we still talk about Darwinism, but the real priority
to the idea of natural selection belongs to the working class Wallace), an
unfortunate disposition in the social sciences to take premature theories too
seriously and to look askance at great experimenters, beautiful writing style,
mocking critiques of the venerable Erasmus Darwin and others who jumped to the
conclusion that insects and other animals think. His experimental manipulations still
present us with the best hope for resolving the question of animal
thinking.
4. The subject of animal thinking is open, and the paradigm shift in ethology towards thinking is unwarranted yet: We must think it possible that animals do not think.
5. We need a
catalog of animal stupidities (e.g., similar to an extant catalog on
deceptions).
6. In any given experiment, before concluding that thinking, or planning, or anticipation, or culture, or anything like that are involved, remove your caterpillar from the tunnel (or . . . tie your elephant to a post, place your lid on the ground, place a bucket on your head).