Morals,
Apes and Us
by Marc D. Hauser
A
female gorilla was seen helping an unconscious 3-year-old
boy. Why did she do that? Did she feel empathy? Can animals
learn to share, cooperate, punish, and show empathy? The following
article tries to answer such questions.
Nearly four years ago, a visitor to
Brookfield Zoo, outside Chicago, captured an extraordinary
event on video. A 3-year-old boy fell into a gorilla enclosure
and was knocked unconscious. Within moments, Binti Jua, a
female gorilla, approached, picked up the unconscious boy,
and cradled him in her arms. Then she walked over and gently
put the boy down in front of the caretaker's door. The
event captured the nation's heart as newspaper headlines blared:
"Gorilla Saves Boy."
Most
reports suggested that Binti rescued the boy because she felt
for him. Although
there is no ambiguity about what the gorilla did, there are
a lot of questions about why. Did she realize the boy was
unconscious? Was she concerned about his well-being? Would
she have acted in the same way toward a conscious boy, a cat,
a teddy bear, or a bag of potato chips?
Despite what the headlines
implied about Binti's moral ,
the answer is by no means clear. Studies by developmental
psychologists Susan Carey and Frank Keil, for example, have
shown that children don't fully grasp the distinction between
a dead being and a live one until they are almost 10 years
old. And
to date, no study of ape intelligence comes close to showing
that orangutans, gorillas, or chimpanzees have
the mental sophistication of a 10-year-old human. We can only
guess why Binti did what she did. And one incident is not
enough to warrant conclusions.
But Binti's actions do raise the public and
scientific interest in the broad question of what mental traits
cause us to behave morally and to what extent other animals
possess those tools. As
a psychologist, I'm interested in the techniques we use to
get at these questions: Can other creatures share,
cooperate, punish cheaters, show empathy, and act
altruistically?
In
a 1988 study, University of Zurich ethnologist Edward Stammbach
set up an experiment with long-tailed macaque monkeys to
test their ability to rein in aggressive behavior and act
cooperatively. First each monkey was trained to
press a lever on a machine to receive a popcorn treat. Once
each animal knew what to do and when, subgroups were created.
Then a low-ranking member in each subgroup was trained to
press a set of levers in a specific sequence that caused the
machine to deliver enough popcorn for three individuals. During
the training, the machine began releasing popcorn only to
the low-ranking specialist.
At first, high-ranking individuals threatened
low-ranking individuals to keep them away from the
altogether. Then the high-ranking individuals learned that
the low-ranking individuals had a unique skill, so they followed
them to the machine and waited to grab all the popcorn. Before
long the low-ranking specialists stopped operating the machine.
But their strike didn't last long. Some higher-ranking individuals
changed their behavior. Rather than chasing specialists away
or eating all their popcorn , they
began to inhibit their aggression. They approached
peacefully and allowed the lower-ranking specialists to eat
a portion of the popcorn. Further, some high-ranking individuals
started grooming specialists more often, even during periods
when the machine was inoperative. Although this attitude change
enabled low-ranking specialists to access food that would
normally be unobtainable, it had no impact on their dominance
rank within the group. Specialists kept their low rank but
were allowed a moment at the high table when their skills
were of use to the royalty.
Other experiments have found that monkeys
even have a rudimentary sense of ownership and respect for
property. Although these might seem to be strictly human concerns,
territorial animals such as sunfish, lizards, sparrows, ad
gibbons are invested in these issues. The space that a territory
owner defends is like its property, and an intruder's respect
reveals its acknowledgment of ownership and property rights.
In a 1991 study, for example, University of
Zurich ethnologists Hans Kummer and Marina Gords tested macaques
that had something other macaques wanted─a see-through tube
filled with raisins. The tube was either fixed to a wall or
freestanding. If it was freestanding, it was attached to a
long or a short piece of rope, or no rope at all. A subordinate
animal was allowed first crack at the tube in all the various
placements. Then researchers observed how the more dominant
individuals reacted. Although dominants often take resources
away from subordinates, the experiments revealed rules underlying
their responses. Consistently, dominants took ownership of
fixed tubes more often than free tubes, and took over free
tubes when the subordinates failed to carry them. Staying
close to the tube and looking at it were not sufficient cues
of ownership from the dominant's perspective. A dominant macaque
would appear to inhibit its impulse to grab the tube if a
subordinate held it close to its body. Here, then, is an intriguing
example of how inhibition plays a crucial role in maintaining
social conventions among monkeys.
But
in any social situation with conventions, individuals often
find that it pays to break the rules. Would such
rule-breakers be punished? To explore this possibility, I
conducted experiments on the island of Cayo Santiago, a research
station near Puerto Rico that is home to some 800 rhesus monkeys.
This particular species has an interesting convention: Unlike
long-tailed macaques, which don't share food, the rhesus monkeys
tend to call out when they find food. In the study, my colleagues
and I located lone individuals and presented them with a small
stash of food. Their first response was to look around, presumably
to decide if there were enemies near. A few individuals waited
and waited and then, as if assuming an infantry combat crouch,
moved cautiously toward the food. Only half the discoverers
called out. When they were detected by other group members,
some were aggressively attacked. Our initial suspicion was
that those who were being attacked were lower-ranking than
those who were not. This hunch turned out to be false. Surprisingly,
both high- and low-ranking individuals were attacked. Whether
or not they were attacked seemed to depend on their vocal
behavior. Silent discoverers who were caught with food were
attacked more often and more severely than those who cried
out. It was as if individuals were being punished for being
inappropriately silent, for deceptively withholding information
about a rich food source.
In a second experiment, we tested peripheral
males, outsiders shifting between groups. Of 26 outsider males who were shown food, not one
called out. They
beelined to the food and either consumed it on the spot or
gobbled a few pieces and then moved to a new location with
a stash. Even if other monkeys discovered them
with the food, the outsiders were never attacked. Thus, it
seemed that members of an established rhesus community abide
by a rule that says: Attack members that find food and don't
share it. And the
seems to be: Why bother risking harm by assaulting onetime
transgressors?
Thus research indicates that animals can inhibit
their impulses and punish those who violate community rules.
But what about empathy? What about Binti? Unless we can establish
that animals understand the thoughts and feelings of others,
we cannot assume that their behavior is moral as humans understand
the word. Codes of moral behavior are founded on beliefs of
right and wrong. How we form those beliefs is based on an
idea of justice, a consideration of how particular actions
affect others. And to understand how our behavior affects
others requires empathy.
Ethnologist Frans de Waal has offered
several observations of apparent empathy among nonhuman
in his 1996 book Good Natured: The Origins of Right and Wrong
in Humans and Other Animals. Richer insights come, however,
from a series of studies published about 40 years ago, when
standards for animal welfare were minimal. Today the experiments
would be deemed unethical, but they do provide a window on
animal emotion that has yet to be opened by more recent scientific
observations.
One experiment was designed by psychologist
Robert Miller and his colleagues to see if a monkey could
interpret another monkey's facial expression, a presumed indicator
of emotion. First, a researcher trained rhesus monkeys to
pull a lever to avoid getting shocked after hearing a specific
sound. Then one of the monkeys─the "actor"─was put in
a room with a lever and a live television image of a second
animal─the "receiver"─that was out of sight and earshot.
The receiver was exposed to the sound that indicated a shock
was coming but lacked a lever to avoid it.
The assumption underlying this experiment
was that the receiver would hear the sound, anticipate the
shock, and show fear on its face. If the actor understood
the receiver's facial expressions, then it would use this
information to pull its lever. If the actor failed, both animals
received a shock. Because shock trials were presented randomly,
and neither animal could hear the other, there was no way
to predict the timing of a response except by using the receiver's
image in the monitor. As it turned out, the actor pulled the
lever significantly more when the receiver heard the sound.
Miller concluded that the actor was able to read the receiver's
facial expressions. Moreover, he and his colleagues suggested
that the animals behaved cooperatively: To avoid the shock,
the receiver gave a signal and the actor read the receiver's
signal.
Did the receivers intend to provide information
to the actors? Was this a cooperative effort? The receivers,
to be sure, must have felt helpless and afraid. But to establish
that they were signaling the actors, one would have to demonstrate
that they were aware of the actors' presence. And, given the
design of the experiment, they certainly were not. Rather,
each receiver's response was elicited by the sound, perhaps
as reflexively as we kick out our foot in response to the
doctor's tiny mallet. It seems likely that the actors picked
up on a change in the activity of the receivers, one that
was consistent enough to predict the shock. But using an expression
to predict a response is not the same as seeing the expression
as an indication of another's emotions at the time.
This
experiment left many loose ends. Although it is
clear that rhesus monkeys can learn to avoid shock by attending
to a facial expression, we don't know if this response is
motivated by empathy, and empathy is necessary for altruism.One has to feel what it would be like to be someone else,
to feel someone else's fear, pain, or joy. We don't know whether
the actors were even aware of the receivers' feelings. There
was no reason for the actors to care. From the actors' perspective,
all that mattered was that the image displayed on the video
monitor functioned as a reliable predictor of shock. A better
experiment would have allowed the actors to see what was happening
to the receiver but restrict the shock to the receiver alone.
In a 1964 study, Jules Maserman and his colleagues
ran a different experiment, again with rhesus monkeys. An
actor was trained to pull one of two chains to receive its
food in response to a brief flash of blue or red light. Next,
a receiver was housed nearby, where the actor could see it.
The experimenter then changed the consequences of responding
to the color of the flash. Pulling in response to one delivered
food; pulling in response to the other delivered both food
to the actor and a severe shock to the receiver. Most actors
pulled the chain delivering the shock far less often than
the chain delivering food only. Two of the 15 actors even
stopped pulling both chains for between 5 to 12 days. When
the actors were paired with new receivers, most continued
to refrain from pulling the chain that delivered the shock.
And pairs that knew each other well tended to show more altruistic
behavior than pairs that were unfamiliar.
What is most remarkable about this last experiment
is the possibility that some monkeys refrained from eating
to avoid injuring another. Perhaps the actors empathized,
imagining what it would be like to receive the shock. Alternatively,
perhaps seeing another monkey grimace in pain is unpleasant
or threatening, and
rhesus monkeys will do whatever they can to avoid unpleasant
conditions. Or perhaps the actor worried that one day it might
be the recipient of a shock. Although refraining from eating
appears to be a response of empathy or sympathy, it may actually
be a selfish response.
As the experiments show, animals are by no
means robots driven solely by instinctual responses. They
are sensitive to their social and ecological environments,
and under certain conditions they can inhibit one response
and favor another. Moreover, they can punish others and sometimes
alleviate another's pain. But no experiment to date has provided
evidence that animals are aware of others' beliefs or intentions.
And without such awareness, there can be no ethical judgment.
Asking what it means to be moral challenges
us to think about how our own capacity for moral agency came
about. Monkeys employ rulelike strategies for promoting the
welfare of a group, including maintaining peace, observing boundaries,
and sharing food. And they can abide by these rules without
necessarily understanding them. Humans are a different kind
of animal: We can consciously evaluate whether behavior is right
or wrong, but we tend to do so depending on the conventions
of our society. In that regard, the roots of our moral intuition
are entwined with the self-interest shown by other animals.
What we don't know is exactly when the uniquely human capacity
for empathy and justice emerged in our ancestors and how cultures
build on a universal moral sense. What is certain is that our
moral potential is still far from fully realized. As Agesilaus,
a Spartan king, said, "If all men were just, there would be
no need of valor."
(2 296 words)
(From Discover, February 2000)
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