Read an Excerpt
Animal Minds
Beyond Cognition to Consciousness
By Donald R. Griffin
University of Chicago Press
Copyright © 2003
University of Chicago
All right reserved.
ISBN: 0-226-30865-0
Chapter One
In Favor of Animal ConsciousnessA hungry chimpanzee walking through his native rain forest comes upon a
large Panda oleosa nut lying on the ground under one of the widely
scattered Panda trees. He knows that these nuts are much too hard to open
with his hands or teeth and that although he can use pieces of wood or
relatively soft rocks to batter open the more abundant Coula edulis nuts,
these tough Panda nuts can only be cracked by pounding them with a very
hard piece of rock. Very few stones are available in the rain forest, but
he walks 80 meters straight to another tree where several days ago he had
cracked open a Panda nut with a large chunk of granite. He carries this
rock back to the nut he has just found, places it in a crotch between two
buttress roots, and cracks it open with a few well-aimed blows. (The loud
noises of chimpanzees cracking nuts with rocks had led early European
explorers to suspect that some unknown native tribe was forging metal
tools in the depths of the rain forest.)
In a city park in Japan, a hungry green-backed heron picks up atwig,
breaks it into small pieces, and carries one of these to the edge of a
pond, where she drops it into the water. At first it drifts away, but she
picks it up and brings it back. She watches the floating twig intently
until small minnows swim up to it, and she then seizes one by a rapid
thrusting grab with her long, sharp bill. Another green-backed heron from
the same colony carries bits of material to a branch extending out over
the pond and tosses the bait into the water below. When minnows approach
this bait, he flies down and seizes one on the wing.
Must we reject, or repress, any suggestion that the chimpanzees or the
herons think consciously about the tasty food they manage to obtain by
these coordinated actions? Many animals adapt their behavior to the
challenges they face either under natural conditions or in laboratory
experiments. This has persuaded many scientists that some sort of
cognition must be required to orchestrate such versatile behavior. For
example, in other parts of Africa chimpanzees select suitable branches
from which they break off twigs to produce a slender probe, which they
carry some distance to poke it into a termite nest and eat the termites
clinging to it as it is withdrawn. Apes have also learned to use
artificial communication systems to ask for objects and activities they
want and to answer simple questions about pictures of familiar things.
Vervet monkeys employ different alarm calls to inform their companions
about particular types of predator.
Such ingenuity is not limited to primates. Lionesses sometimes cooperate
in surrounding prey or drive prey toward a companion waiting in a
concealed position. Captive beaver have modified their customary patterns
of lodge- and dam-building behavior by piling material around a vertical
pole at the top of which was located food that they could not otherwise
reach. They are also very ingenious at plugging water leaks, sometimes
cutting pieces of wood to fit a particular hole through which water is
escaping. Under natural conditions, in late winter some beaver cut holes
in the dams they have previously constructed, causing the water level to
drop, which allows them to swim about under the ice without holding their
breath.
Nor is appropriate adaptation of complex behavior to changing
circumstances a mammalian monopoly. Bowerbirds construct and decorate
bowers that help them attract females for mating. Plovers carry out
injury-simulating distraction displays that lead predators away from their
eggs or young, and they adjust these displays according to the intruder's
behavior. A parrot uses imitations of spoken English words to ask for
things he wants to play with and to answer simple questions such as
whether two objects are the same or different, or whether they differ in
shape or color. Even certain insects, specifically the honeybees, employ
symbolic gestures to communicate the direction and distance their sisters
must fly to reach food or other things that are important to the colony.
These are only a few of the more striking examples of versatile behavior
on the part of animals that will be discussed in the following pages.
Although these are not routine everyday occurrences, the fact that animals
are capable of such versatility has led to a subtle shift on the part of
some scientists concerned with animal behavior. Rather than insisting that
animals do not think at all, many scientists now believe that they
sometimes experience at least simple thoughts, although these thoughts are
probably different from any of ours. For example, Terrace (1987, 135)
closed a discussion of "thoughts without words" as follows: "Now that
there are strong grounds to dispute Descartes' contention that animals
lack the ability to think, we have to ask just how animals do think."
Because so many cognitive processes are now believed to occur in animal
brains, it is more and more difficult to cling to the conviction that this
cognition is never accompanied by conscious thoughts.
Conscious thinking may well be a core function of central nervous systems.
For conscious animals enjoy the advantage of being able to think about
alternative actions and select behavior they believe will get them what
they want or help them avoid what they dislike or fear. Of course, human
consciousness is astronomically more complex and versatile than any
conceivable animal thinking, but the basic question addressed in this book
is whether the difference is qualitative and absolute or whether animals
are conscious even though the content of their consciousness is
undoubtedly limited and very likely quite different from ours. There is of
course no reason to suppose that any animal is always conscious of
everything it is doing, for we are entirely unaware of many complex
activities of our bodies. Consciousness may occur only rarely in some
species and not at all in others, and even animals that are sometimes
aware of events that are important in their lives may be incapable of
understanding many other facts and relationships. But the capability of
conscious awareness under some conditions may well be so essential that it
is the sine qua non of animal life, even for the smallest and simplest
animals that have any central nervous system at all. When the whole system
is small, this core function may therefore be a larger fraction of the
whole.
The fact that we are consciously aware of only a small fraction of what
goes on in our brains has led many scientists to conclude that
consciousness is an epiphenomenon or trivial by-product of neural
functioning, as discussed by Harnad (1982). But the component of central
nervous system activity of which we are consciously aware is of special
significance, because it is what makes life real and important to us, as
discussed in detail by Siewert (1998). Insofar as other species are
conscious, the same importance may well be manifest. Animals may carry out
much of their behavior quite unconsciously. Many may never be conscious at
all. But insofar as they are conscious, this is an important attribute.
Although nonconscious information processing could in theory produce the
same end result as conscious thinking, as emphasized by Shettleworth
(1998) and others, it seems likely that conscious thinking and emotional
feeling about current, past, and anticipated events is the best way to
cope with some of the more critical challenges faced by animals in their
natural lives. As pointed out by the philosopher Karl Popper (1978), what
he termed "mental powers" are very effective in coping with novel and
unpredictable challenges. This is especially true of many animals under
natural conditions, where mistakes are often fatal. The effectiveness of
conscious thinking and guiding behavioral choices on the basis of
emotional feelings about what is liked or disliked may well be so great
that this core function is one of the most important activities of which
central nervous systems are capable.
The nature of animal minds was a major subject of investigation until it
was repressed by behaviorism, as discussed in chapter 2. Darwin, Romanes,
Lloyd Morgan, von Uexkull, and many other scientists of the nineteenth and
early twentieth centuries were deeply interested in animal mentality. This
history has been thoroughly reviewed by Schultz (1975), Wasserman (1981),
Boakes (1984), Dewsbury (1984), and R. J. Richards (1987), and especially
cogently by Burghardt (1985a, 1985b). What is new is the accumulated
results of a century of active and successful investigation of animal
behavior. These discoveries have now provided a wealth of data about the
complexities and versatility of animal behavior under natural conditions,
and what they can learn to do in the laboratory. We can therefore return
to the investigation of animal minds with far better and more extensive
evidence than what was available to nineteenth-century biologists.
I will take it for granted that behavior and consciousness (human and
nonhuman) result entirely from events that occur in their central nervous
systems. In other words, I will proceed on the basis of emergent
materialism as analyzed by Bunge (1980, 6), Bunge and Ardilla (1987, 27),
and Mahner and Bunge (1997, 205-12), and assume that subjective
consciousness is an activity of central nervous systems, which are of
course part of the physical universe. Just what sort of neural activity
leads to consciousness remains a challenging mystery, as I will discuss in
detail in chapter 8. But there is no need to call upon immaterial,
vitalistic, or supernatural processes to explain how some fraction of
human or animal brain activity results in conscious, subjective thoughts
and feelings.
Defining Consciousness
No one seriously denies that we experience conscious thoughts and
subjective feelings, even though we cannot describe them with complete
accuracy and therefore no one else can experience them exactly as we do.
The question under consideration in this book is the extent to which
nonhuman animals also experience something of the same general nature as
the subjective feelings and conscious thoughts that we know at first hand.
The content of an animal's conscious experience may be quite different
from any human experience. It may ordinarily be limited to what the animal
perceives at the moment about its immediate situation, but sometimes its
awareness probably includes memories of past perceptions or anticipations
of future events. An animal's understanding may be accurate or misleading,
and the content of its thoughts may be simple or complex. A conscious
animal must often experience some feeling about whatever engages its
attention. Furthermore, any thinking animal is likely to guide its
behavior at least partly on the basis of the content of its thoughts,
however simple or limited these may be.
In their Dictionary of Ethology Immelmann and Beer (1989) define animal
consciousness as "immediate awareness of things, events, and relations,"
but they hasten to add the conventional behavioristic claim that
"statements about the nature of this awareness in comparison to that of
humans are dismissed by tough-minded scientists as idle speculation." But
speculation is where scientific investigation often begins, and I hope to
stimulate new and enterprising inquiries that will significantly reduce
our current ignorance. Consciousness is not a neat homogeneous entity;
there are obviously many kinds and degrees of consciousness. Many
scientists (for example, Hauser 2000, xiii) feel that terms such as
consciousness are too vague and slippery to be useful in scientific
investigation, and they are very reluctant even to begin talking about the
possibility of nonhuman consciousness without first settling on clear-cut
definitions. On the other hand, Francis Crick (1994, 20) is not so easily
inhibited:
Everyone has a rough idea of what is meant by consciousness. It is
better to avoid a precise definition of consciousness because of the
dangers of premature definitions. Until the problem is understood much
better, any attempt at a formal definition is likely to be either
misleading or overly restrictive or both. If this seems like cheating,
try defining for me the word gene. So much is now known about genes that
any simple definition is likely to be inadequate. How much more
difficult, then, to define a biological term when rather little is known
about it.
Semantic Piracy
An unnecessary confusion has arisen concerning the meanings attached to
terms such as awareness, emotion, mind, and conscious. In ordinary usage
they denote conscious mental states, but many scientists justify their
aversion to these terms and the concepts they designate by arguing that
they cannot be defined with the precision necessary for scientific
analysis. This has led to a sort of semantic piracy committed by defining
mental states in essentially behavioristic terms. Such terms as positive
or negative emotion replace like or fear when a living or even a nonliving
system is more likely to respond in one way than another, ruling out
implicitly by choice of terms subjective experiences such as liking or
fearing. Crist (1996, 1998, 1999) has lucidly analyzed the pervasive
effect of this "mechanomorphic" terminology. Thinking is often redefined
explicitly or implicitly as information processing. Calling it cognition
has become a popular way to study animal mentality without recognizing
that at least some of the cognition is probably accompanied, and
influenced, by conscious subjective experiences.
The Content of Animal Consciousness
Animal thoughts and emotions presumably concern matters of immediate
importance to the animals themselves, rather than kinds of conscious
thinking that are primarily relevant to human affairs. Consciousness is
not an all-or-nothing attribute. It varies widely within our species, and
it would be remarkable if the content of every animal's consciousness were
identical. Conscious thinking and strong emotional feelings can ordinarily
deal with only one or a very few things at a time. Large, complex animals
must also be able to organize and retain information about innumerable
perceptions and potential actions of which only one or a very few can be
the focus of conscious awareness at any one moment.
Recognizing that an animal's consciousness may be quite different from any
human thoughts and feelings makes the problem of identifying and analyzing
it more difficult. We may, however, tend to exaggerate this difficulty,
because many basic concerns are likely to be very similar for most animals
that have any conscious experiences at all.
Continues...
Excerpted from Animal Minds
by Donald R. Griffin
Copyright © 2003
by University of Chicago.
Excerpted by permission.
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