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Francisco J. Ayala, Ph.D.
University of California, Irvine
REPUBLISHED WITH KIND PERMISSION FROM JONES AND BARTLETT PUBLISHERS:
AYALA, FRANCISCO J. (1994), BIOLOGY, ETHICS, AND THE ORIGINS OF LIFE:
"THE DIFFERENCES OF BEING HUMAN," HOLMES ROLSTON, III, ED.
BOSTON: JONES AND BARTLESS PUBLISHERS, PP. 117-135.
1. Asummary of the Argument
The last common ancestors to humans and apes lived some eight million
years ago. The first hominids were the Australopithecines, who appeared
four million years ago; they had a bipedal gait and small brains (about
400 cubic centimeters). The hominid brain gradually increased in size,
reaching 1,400 cc within the last one hundred thousand years. Simple stone
tools were first made by our ancestors two million years ago; more complex
and diversified tools only came about one hundred thousand years ago.
Erect posture and large brain are distinctive anatomical features of
modern humans. High intelligence, symbolic language, political institutions,
technology, religion, and ethics are some of the behavioral traits that
distinguish us from other animals. An explanation of human evolution must
account for the various anatomical and behavioral traits in terms of natural
selection (and other evolutionary processes). One explanatory strategy
is to focus on a particular human feature and seek to identify the conditions
under which this feature may have been favored by natural selection. Such
a strategy may lead to erroneous conclusions as a consequence of the fallacy
of selective attention: some traits may have come about not because they
are themselves adaptive, but rather because they are associated with other
traits that are favored by natural selection. Geneticists have long recognized
the phenomenon of "pleiotropy," the expression of one particular
gene in several different organs or anatomical traits. It follows that
a gene that becomes changed owing to its effects on a selected trait will
result in the modification of other traits as well.
Literature, art, science, technology, and other behavioral features may
have come about not because they were adaptively favored in human evolution,
but because they are expressions of the high intellectual abilities present
in modern humans: what was favored by natural selection (its "target")
was an increase in intellectual ability rather than each one of those
particular activities. I argue here that ethical behavior (the proclivity
to judge human actions as either good or evil) has evolved as a distinctive
trait of human behavior not because it was adaptive in itself, but rather
as a pleiotropic consequence of the high intelligence characteristic of
humans.
I first point out that the question of whether ethical behavior is biologically
determined may refer either to the capacity for ethics (i.e., the proclivity
to judge human actions as either right or wrong) or to the moral norms
accepted by human beings for guiding their actions. My theses are: (1)
that the capacity for ethics is a necessary attribute of human nature;
and (2) that moral norms are products of cultural evolution, not of biological
evolution.
Humans exhibit ethical behavior by nature because their biological makeup
determines the presence of the three necessary, and jointly sufficient,
conditions for ethical behavior: (a) the ability to anticipate the consequences
of one's own actions; (b) the ability to make value judgments; and (c)
the ability to choose between alternative courses of action. Ethical behavior
came about in evolution not because it is adaptive in itself, but as a
necessary consequence of man's eminent intellectual abilities, which are
an attribute directly promoted by natural selection.
Since Darwin's time, there have been evolutionists proposing that the
norms of morality are derived from biological evolution. Some sociobiologists
have recently developed a quite subtle version of that proposal. The sociobiologists'
argument is that human ethical norms are socioculrural correlates of behaviors
fostered by biological evolution. I argue that such proposals are misguided
and do not escape the naturalistic fallacy. Perhaps it is true that both
natural selection and moral norms sometimes coincide on the same behavior.
The two are consistent. But this isomorphism between the behaviors promoted
by natural selection and those sanctioned by moral norms exists only with
respect to the consequences of the behaviors; the underlying causations
are completely disparate.
2. Ethics and Language: A Parallel Distinction
I just noted that the question of whether ethical behavior is biologically
determined may refer to either of the following issues: (1) Is the capacity
for ethics--the proclivity to judge human actions as either right or wrong--determined
by the biological nature of human beings? (2) Are the systems or codes
of ethical norms accepted by human beings biologically determined? A similar
distinction can be made with respect to language. The issue of whether
the capacity for symbolic language is determined by our biological nature
is different from the question of whether the particular language we speak
(English, Spanish, or Japanese) is biologically necessary.
The first question is more fundamental; it asks whether or not the biological
nature of Homo sapiens is such that humans are necessarily inclined to
make moral judgments and to accept ethical values, to identify certain
actions as either right or wrong. Affirmative answers to this first question
do not necessarily determine what the answer to the second question should
be. Independently of whether or not humans are necessarily ethical, it
remains to be determined whether particular moral prescriptions are in
fact determined by our biological nature, or whether they are chosen by
society, or by individuals. Even if we were to conclude that people cannot
avoid having moral standards of conduct, it might be that the choice of
the particular standards used for judgment would be arbitrary. Or that
it depended on some other, nonbiological criteria. The need for having
moral values does not necessarily tell us what these moral values should
be, just as the capacity for language does not determine which language
we shall speak.
The thesis that I propose is that humans are ethical beings by their
biological nature. Humans' evaluate their behavior as either right or
wrong, moral or immoral, as a consequence of their eminent intellectual
capacities which include self-awareness and abstract thinking. These intellectual
capacities are products of the evolutionary process, but they are distinctively
human. Thus, I maintain that ethical behavior is not causally related
to the social behavior of animals, including kin, and reciprocal "altruism."
A second thesis that I put forward is that the moral norms according
to which we evaluate particular actions as morally either good or bad
(as well as the grounds that may be used to justify the moral norms) are
products of cultural evolution, not of biological evolution. The norms
of morality belong, in this respect, to the same category of phenomena
as the languages spoken by different peoples, their political and religious
institutions, and the arts, sciences, and technology. The moral codes,
like these other products of human culture, are often consistent with
the biological predispositions of the human species, dispositions we may
to some extent share with other animals. But this consistency between
ethical norms and biological tendencies is not necessary or universal:
it does not apply to all ethical norms in a given society, much less in
all human societies.
Moral codes, like any other dimensions of cultural systems, depend on
the existence of human biological nature and must be consistent with it
in the sense that they could not counteract it without promoting their
own demise. Moreover, the acceptance and persistence of moral norms is
facilitated whenever they are consistent with biologically conditioned
human behaviors. But the moral norms are independent of such behaviors
in the sense that some norms may not favor, and may hinder, the survival
and reproduction of the individual and its genes, which are the targets
of biological evolution. Discrepancies between accepted moral rules and
biological survival are, however, necessarily limited in scope or would
otherwise lead to the extinction of the groups accepting such discrepant
rules.
3. The Necessary Conditions for Ethical Behavior
The question of whether ethical behavior is determined by our biological
nature must be answered in the affirmative. By "ethical behavior"
I mean here to refer to the urge to judge human actions as either good
or bad, which need not require actually choosing good behavior (i.e.,
choosing to do what is perceived as good instead of what is perceived
as evil). Humans exhibit ethical behavior by nature because their biological
constitution determines the presence in them of the three necessary, and
jointly sufficient, conditions for ethical behavior. These conditions
are (a) the ability to anticipate the consequences of one's own actions;
(b) the ability to make value judgments; and (c) the ability to choose
between alternative courses of action. I shall briefly examine each of
these abilities and show that they exist as a consequence of the eminent
intellectual capacity of human beings.
The ability to anticipate the consequences of one's own actions is the
most fundamental of the three conditions required for ethical behavior.
Only if I can anticipate that pulling the trigger will shoot the bullet,
which in turn will strike and kill my enemy, can the action of pulling
the trigger be evaluated as nefarious. Pulling a trigger is not in itself
a moral action; it becomes so by virtue of its relevant consequences.
My action has an ethical dimension only if I anticipate these consequences.
The ability to anticipate the consequences of one's actions is closely
related to the ability to establish the connection between means and ends;
that is, of seeing a mean precisely as mean, as something that serves
a particular end or purpose. This ability to establish the connection
between means and their ends requires the ability to anticipate the future
and to form mental images of realities not present or not yet in existence.
The ability to establish the connection between means and ends happens
to be the fundamental intellectual capacity that has made possible the
development of human culture and technology. The evolutionary roots of
this capacity may be found in the evolution of the erect position, which
transformed the anterior limbs of our ancestors from organs of locomotion
into organs of manipulation. The hands thereby gradually became organs
adept for the construction and use of objects for hunting and other activities
that improved survival and reproduction, that is, they increased the reproductive
fitness of their carriers. The construction of tools depends not only
on manual dexterity, but in perceiving them precisely as tools, as objects
that help to perform certain actions, that is, as means that serve certain
ends or purposes: a knife for cutting, an arrow for hunting, an animal
skin for protecting the body from the cold. Natural selection promoted
the intellectual capacity of our biped ancestors, because increased intelligence
facilitated the perception of tools as tools, and therefore their construction
and use, with the ensuing amelioration of biological survival and reproduction.
The development of the intellectual abilities of our ancestors took place
over two million years or longer, gradually increasing the ability to
connect means with their ends and, hence, the possibility of making ever
more complex tools serving remote purposes. The ability to anticipate
the future, essential for ethical behavior, is therefore closely associated
with the development of the ability to construct tools, an ability that
has produced the advanced technologies of modern societies and that is
largely responsible for the success of humankind as a biological species.
From its obscure beginnings in Africa, humankind has spread over the whole
earth except the frozen wastes of Antarctica, and has become the most
numerous species of mammal. Numbers may not be an unmixed blessing, but
they are a measure of biological success.
The second condition for the existence of ethical behavior is the ability
to make value judgments, to perceive certain objects or deeds as more
desirable than others. Only if I can see the death of my enemy as preferable
to his or her survival (or vice versa) can the action leading to his or
her demise be thought as moral. If the alternative consequences of an
action are neutral with respect to value, the action cannot be characterized
as ethical. The ability to make value judgments depends on the capacity
for abstraction, that is, on the capacity to perceive actions or objects
as members of general classes. This makes it possible to compare objects
or actions with one another and to perceive some as more desirable than
others. The capacity for abstraction requires an advanced intelligence
such as exists in humans and apparently in them alone.
The third condition necessary for ethical behavior is the ability to
choose between alternative courses of action. Pulling the trigger can
be a moral action only if/have the option not to pull it. A necessary
action beyond our control is not a moral action: the circulation of the
blood or the process of food digestion are not moral actions.
Whether there is free will is a question much discussed by philosophers,
and this is not the appropriate place to review the arguments. I will
only advance two considerations that are common-sense evidence of the
existence of free will. One is our personal experience, which indicates
that the possibility to choose between alternatives is genuine rather
than only apparent. The second consideration is that when we confront
a given situation that requires action on our part, we are able mentally
to explore alternative courses of action, thereby extending the field
within which we can exercise our free will. In any case, if there were
no free will, there would be no ethical behavior; morality would only
be an illusion. The point that I want to make here is, however, that free
will is dependent on the existence of a well-developed intelligence, which
makes it possible to explore alternative courses of action and to choose
one or another in view of the anticipated consequences.
In summary, ethical behavior is an attribute of the biological make-up
of humans and, hence, is a product of biological evolution. But I see
no evidence that ethical behavior developed because it was adaptive in
itself. I find it hard to see how evaluating certain actions as either
good or evil (not just choosing some actions rather than others, or evaluating
them with respect to their practical consequences) would promote the reproductive
fitness of the evaluators. Nor do I see how there might be some form of
"incipient" ethical behavior that would then be promoted by
natural selection. The three necessary conditions for there being ethical
behavior are manifestations of advanced intellectual abilities.
It rather seems that the target of natural selection was the development
of these advanced intellectual capacities. This development was favored
by natural selection because the construction and use of tools improved
the strategic position of our biped ancestors. Once bipedalism evolved
and tool-using and tool-making became possible, those individuals more
effective in these functions had a greater probability of biological success.
The biological advantage provided by the design and use of tools persisted
long enough so that intellectual abilities continued to increase, eventually
yielding the eminent development of intelligence that is characteristic
of Homo sapiens.
4. Moral Codes: A Cultural Legacy
I have answered in the affirmative the first of the two questions i posed:
ethical behavior is rooted in the biological make-up of humans. I have
also proposed that ethical behavior did not evolve because it was adaptive
in itself, but rather as the indirect outcome of the evolution of eminent
intellectual abilities. Now I turn to the second question: whether our
biological nature also determines which moral norms or ethical codes human
beings must obey. My answer is negative. The moral norms according to
which we decide whether a particular action is either right or wrong are
not specified by biological evolution but by cultural evolution. The premises
of our moral judgments are received from religious and other social traditions.
I hasten to add, however, that moral systems, like any other cultural
activities, cannot long survive if they run outright contrary to our biology.
The norms of morality must be consistent with biological nature, because
ethics can only exist in human individuals and in human societies. One
might therefore also expect, and it is the case, that accepted norms of
morality will often promote behaviors that increase the biological adaptation
of those who behave according to them. But this is neither necessary nor
indeed always the case.
5. Theories of Morality
There are many theories concerned with the rational grounds for morality,
such as deductive theories that seek to discover the axioms or fundamental
principles that determine what is morally correct on the basis of direct
moral intuition; or theories like logical positivism or existentialism,
which negate rational foundations for morality, reducing moral principles
to emotional decisions or to other irrational grounds. Since the publication
of Darwin's theory of evolution by natural selection, philosophers as
well as biologists have attempted to find in the evolutionary process
the justification for moral norms. The common ground to all such proposals
is that evolution is a natural process that achieves goals that are desirable
and thereby morally good; indeed, it has produced humans. Proponents of
these ideas claim that only the evolutionary goals can give moral value
to human action: whether a human deed is morally right depends on whether
it directly or indirectly promotes the evolutionary process and its natural
objectives.
Herbert Spencer was perhaps the first philosopher seeking to find the
grounds of morality in biological evolution. More recent attempts include
those of the distinguished evolutionists Julian S. Huxley (1947, 1953)
and C.H. Waddington (1960) and of Edward O. Wilson (1975, 1978), founder
of sociobiology as an independent discipline engaged in discovering the
biological foundations of all social behavior.
In The Principles of Ethics (1893), Spencer seeks to replace the
Christian faith as the justification for traditional ethical values with
a natural foundation. Spencer argues that the theory of organic evolution
implies certain ethical principles. Human conduct must be evaluated, like
any biological activity whatsoever, according to whether or not it conforms
to the life process; therefore, any acceptable moral code must be based
on natural selection, the law of struggle for existence. According to
Spencer, the most exalted form of conduct is that which leads to a greater
duration, extension, and perfection of life; the morality of all human
actions must be measured by that standard. Spencer proposes that, although
exceptions exist, the general rule is that pleasure goes with that which
is biologically useful, whereas pain marks what is biologically harmful.
These associations are an outcome of natural selection--thus, while doing
what brings them pleasure and avoiding what is painful, organisms improve
their chances for survival. With respect to human behavior, we see that
we derive pleasure from virtuous behavior and pain from evil actions,
associations which indicate that the morality of human actions is also
rounded on biological nature.
Spencer proposes, as the general rule of human behavior, that anyone
should be free to do anything he or she wants, so long as it does not
interfere with the similar freedom to which others are entitled. The justification
of this rule is found in organic evolution: the success of an individual,
plant, or animal depends on its ability to obtain that which it needs.
Consequently, Spencer reduces the role of the state to protecting the
collective freedom of individuals to do as they please. This laissez
faire form of government may seem ruthless, because individuals would
seek their own welfare without any consideration for others (except for
respecting their freedom), but Spencer believes that it is consistent
with traditional Christian values. It should be added that although Spencer
sets the grounds of morality on biological nature and on nothing else,
he admits that certain moral norms go beyond that which is biologically
determined; these are rules formulated by society and accepted by tradition.
Social Darwinism, in Spencer's version or in some variant form, was fashionable
in European and American circles during the latter part of the nineteenth
century and the early years of the twentieth, but it has few or no distinguished
intellectual followers at present. Spencer's critics include the evolutionists
Julian S. Huxley and C.H. Waddington who, nevertheless, maintain that
organic evolution provides grounds for a rational justification of ethical
codes. For Huxley, the standard of morality is the contribution that actions
make to evolutionary progress, which goes from less to more "advanced"
organisms. For Waddington, the morality of actions must be evaluated by
their specific contribution to furthering human evolution.
Huxley's and Waddington's views are based on value judgments about what
is or is not progressive in evolution. Contrary to Huxley's proposal,
there is nothing objective in the evolutionary process itself (i.e., outside
human considerations; see Ayala, 1982a) that makes the success of bacteria,
which have persisted as such for more than two billion years and in enormous
numbers, less "progressive" than that of the vertebrates, even
though the latter are more complex. Nor are the insects, of which more
than one million species exist, less successful or less progressive from
a purely biological perspective than humans or any other mammal species.
Waddington fails to demonstrate why the promotion of human biological
evolution by itself should be the standard used to measure what is morally
good.
6. The Naturalistic Fallacy
A more fundamental objection against the theories of spencer, huxley,
and Waddington--and against any other program seeking the justification
of a moral code in biological nature--is that such theories commit the
"naturalistic fallacy" (Moore, 1903), which consists in identifying
what "is" with what "ought to be." This error was
pointed out already by Hume:
In every system of morality which i have hitherto met with i have always
remarked that the author proceeds for some time in the ordinary way
of reasoning... when of a sudden i am surprised to find, that instead
of the usual copulations of propositions, is and is not,
I meet with no proposition that is not connected with an ought
or ought not. This change is imperceptible; but is, however,
of the last consequence. For as this ought or ought not
expresses some new relation or affirmation, it is necessary that it
should be observed and explained; and at the same time a reason should
be given, for what seems altogether inconceivable, how this new relation
can be a deduction from others, which are entirely different from it.
(Hume, [1740]1978, p. 469)
The naturalistic fallacy occurs whenever inferences using the terms ought
or ought not are derived from premises that do not include such
terms but are rather formulated using the connections is or/s not. An
argument cannot be logically valid unless the conclusions contain only
terms that are also present in the premises. In order to proceed logically
from that which "is" to what "ought to be," it is
necessary to include a premise that justifies the transition between the
two expressions. But this transition is what is at stake, and one would
need a previous premise to justify the validity of the one making the
transition, and so on in a regression ad infinitum. In other words,
from the fact that something is the case, it does not follow that it ought
to be so in the ethical sense; is and ought belong to
disparate logical categories.
Because evolution has proceeded in a particular way, it does not follow
that that course is morally right or desirable. The justification of ethical
norms on biological evolution or on any other natural process can only
be achieved by introducing value judgments, human choices that prefer
one over another biological result or process. Biological nature is in
itself morally neutral.
It must be noted, moreover, that using natural selection or the course
of evolution for determining the morality of human actions may lead to
paradoxes. Evolution has produced the smallpox and AIDS viruses. But it
would seem unreasonable to accuse the World Health Organization of immorality
because of its campaign for total eradication of the smallpox virus, or
to label unethical the efforts to control the galloping spread of the
AIDS virus. Human hereditary diseases are conditioned by mutations that
are natural events in the evolutionary process. But we do not think it
immoral to cure or alleviate the pain of persons with such diseases. Natural
selection is a natural process that increases the frequency of certain
genes and eliminates others, that yields some kinds of organisms rather
than others; but it is not a process moral or immoral in itself or in
its outcome, in the same way as gravity is not a morally laden force.
In order to consider some evolutionary events as morally right and others
wrong, we must introduce human values. Moral evaluations cannot be reached
simply on the basis that certain events came about by natural processes.
7. Sociobiology's Proposal: Biology Standing on its Head
Edward O. Wilson has urged that "scientists and humanists should
consider together the possibility that the time has come for ethics to
be removed temporarily from the hands of the philosophers and biologicized"
(Wilson, 1975, p. 562). Wilson, like other sociobiologists (Barash, 1977;
Wilson, 1978; Alexander, 1979; see also Ruse, 1986, and Ruse, Chapter
4), believes that sociobiology may provide the key for finding a naturalistic
basis for ethics. Sociobiology is "the systematic study of the biological
basis of all forms of social behavior in all kinds of organisms"
(Wilson, 1977) or, in Barash's concise formulation, "the application
of evolutionary biology to social behavior" (Barash, 1977, p. ix).
Its purpose is "to develop general laws of the evolution and biology
of social behavior, which might then be extended in a disinterested manner
to the study of human beings" (Wilson, 1977, p. ix). The program
is ambitious: to discover the biological basis of human social behavior,
starting from the investigation of the social behavior of animals.
The sociobiologist's argument concerning normative ethics is not that
the norms of morality can be grounded in biological evolution, but rather
that evolution predisposes us to accept certain moral norms, namely those
that are consistent with the "objectives" of natural selection.
Because of this predisposition, human' moral codes sanction patterns of
behavior similar to those encountered in the social behavior of animals.
The sociobiologists claim that the agreement between moral codes and the
goals of natural selection in social groups was discovered when the theories
of kin selection and reciprocal altruism were formulated. The commandment
to honor one's parents, the incest taboo, the greater blame usually attributed
to the wife's adultery than to the husband's, and the ban or restriction
of divorce are among the numerous ethical precepts that endorse behaviors
that are also endorsed by natural selection, as has been discovered by
sociobiology.
The sociobiologists sometimes reiterate their conviction that science
and ethics belong to separate logical realms, that one may not infer what
is morally right or wrong from a determination of how things are or are
not in nature. According to Wilson, "To devise a naturalistic description
of human social behavior is to note a set of facts for further investigation,
not to pass a value judgment or to deny that a great deal of the behavior
can be deliberately changed if individual societies so wish" (1977,
p. xiv). Barash puts it this way: "Ethical judgments have no place
in the study of human sociobiology or in any other science for that matter.
What is biological is not necessarily good" (1977, p. 278). Alexander
asks what it is that evolution teaches us about normative ethics or about
what we ought to do and responds, "Nothing whatsoever"
(1979, p. 276).
There is nevertheless some question as to whether the sociobiologists
are always consistent with the statements just quoted. Ruse, for instance,
defending the sociobiologists, seems to take the is that has resulted
from natural selection operating to produce preferences within us and
identify it with the ought of moral life: "The good is simply
that which evolution through selection has led us to regard as good"
(Ruse, 1984, p. 93). In humans, whatever norms and values have been selected
for are ipso facto good.
Wilson writes that "the requirement for an evolutionary approach
to ethics is self-evident. It should also be clear that no single set
of moral standards can be applied to all human populations, let alone
all sex-age classes within each population. To impose a uniform code is
therefore to create complex, intractable moral dilemmas" (Wilson,
1975, p. 564). Moral pluralism is, for Wilson, "innate." Biology,
then, at the very least helps us to decide that certain moral codes (e.g.,
all those pretending to be universally applicable) are incompatible with
human nature and, therefore, are unacceptable. This is not quite an argument
in favor of the biological determinism of ethical norms, but it does approach
determinism from the negative side: because the range of valid moral codes
is delimited by the claim that some are not compatible with biological
nature.
However, Wilson goes further when he writes: "Human behavior-like
the deepest capacities for emotional response which derive and guide it--is
the circuitous technique by which human genetic material has been and
will be kept intact. Morality has no other demonstrable ultimate function"
(Wilson, p. 978, p. 167, emphasis added). How is one to interpret this
statement? It is possible that Wilson is simply giving the reason why
ethical behavior exists at all. His proposition would, then, be that humans
are prompted to evaluate morally their actions as a means to preserve
their genes, their biological nature. But this proposition is erroneous.
Human beings are by nature ethical beings in the sense I have expounded
earlier: they judge morally their actions because of their innate ability
for anticipating the consequences of their actions, for formulating value
judgments, and for free choice. Human beings exhibit ethical behavior
by nature and necessity, rather than because such behavior would help
to preserve their genes or serve any other purpose.
Alternatively, Wilson's statement may be read as a justification of human
moral codes: the moral codes' function would be to preserve human genes.
But this would entail the naturalistic fallacy and, worse yet, would seem
to justify a morality that most of us detest. If the preservation of human
genes is the purpose that moral norms serve, Spencer's Social Darwinism
would seem right; racism or even genocide could be justified as morally
correct if they were perceived as the means to preserve those genes thought
to be good or desirable and to eliminate those thought to be bad or undesirable.
There is no doubt in my mind that Wilson is not intending to justify racism
or genocide, but this is one possible interpretation of his words.
8. Kin Selection and Animal "Altruism"
I shall now turn to the sociobiologists' proposition that natural selection
favors in animals behaviors that are isomorphic with those behaviors that
are sanctioned by the moral codes endorsed by most humans.
Evolutionists had for years struggled with finding an explanation for
the apparently altruistic behavior of animals. When a predator attacks
a herd of zebras, they will attempt to protect the young in the herd,
even if they are not their progeny, rather than fleeing. When a prairie
dog sights a coyote, it will warn other members of the colony with an
alarm call, even though by drawing attention to itself this increases
its own risk. There are quite numerous examples of altruistic behaviors
of this kind.
Altruism is defined in the dictionary I have at hand (Webster's New Collegiate,
2nd ed.) as "regard for, and devotion to, the interests of others."
Yet, to speak of animal altruism is not to claim that explicit feelings
of devotion or regard are present, but rather that animals act for the
welfare of others at their own risk, just as humans are expected to do
when behaving altruistically. Regardless of what motivations are or are
not present, biologists encounter the problem of how to justify such behaviors
in terms of natural selection. Assume, for illustration, that in a certain
species there are two alternative forms of a gene ("alleles"),
of which one but not the other promotes altruistic behavior. Individuals
possessing the altruistic allele will risk their life for the benefit
of others, whereas those possessing the nonaltruistic allele will benefit
from the altruistic behavior of their peers without risking themselves.
Possessors of the altruistic allele will be more likely to die, and the
altruistic allele will therefore be eliminated more often than the nonaltruistic
allele. Eventually, after some generations, the altruistic allele will
be completely replaced by the nonaltruistic one. But then how is it that
altruistic behaviors are common in animals without the benefit of ethical
motivation?
One major contribution of sociobiology to evolutionary theory is the
notion of "inclusive fitness." In order to ascertain the consequences
of natural selection, it is necessary to take into account a gene's effects
not only on a particular individual but on all individuals possessing
that gene. When considering altruistic behavior, we have to weigh not
only the risks for the altruistic individual but also the benefits for
other possessors of the same allele. Zebras live in herds composed of
blood relatives. An allele prompting adults to protect the defenseless
young would be favored by natural selection if the benefit (in terms of
saving the lives of individuals carrying the same allele) is greater than
the cost (due to the increased risk of the protectors). An individual
that lacks the altruistic allele and carries instead a nonaltruistic one
will not risk its life, but the nonaltruistic allele is partially eradicated
with the death of each defenseless relative.
It follows from this line of reasoning that the more closely related
the members of a herd or animal group typically are, the more altruistic
behavior should be present. This seems generally to be the case. We need
not enter here into the details of the quantitative theory developed by
sociobiologists in order to appreciate the significance of two examples.
The most obvious is parental care. Parents feed and protect their young
because each child has half the genes of each parent: the genes are protecting
themselves, as it were, when they prompt a parent to care for its young.
The second example is more subtle: the social organization and behavior
of certain animals like the honeybee. Worker bees toil building the hive
and feeding and caring for the larvae even though they themselves are
sterile and only the queen produces progeny. Assume that in some ancestral
hive, an allele arises that prompts worker bees to behave as they now
do. It would seem that such an allele would not be passed on to the following
generation because such worker bees do not reproduce. But such inference
is erroneous. Queen bees produce two kinds of eggs: those that remain
unfertilized develop into males (which are therefore "hap1oid,"
i.e., carry only one set of genes); others are fertilized (hence, are
"diploid," i.e., carry two sets of genes) and develop into worker
bees and occasionally into a queen. W.D. Hamilton (1964) demonstrated
that, with such a reproductive system, daughter queens and their worker
sister, share in two-thirds of their genes, whereas daughter queens and
their mother share in only one-half of their genes. Hence, the worker
bee genes are more effectively propagated by workers caring for their
sisters than i they would produce and care for their own daughters. Natural
selection can thus explain the existence in social insects of sterile
casts, which exhibit a most extreme form of apparently altruistic behavior
by dedicating their life to care for the progeny of another individual
(the queen).
Sociobiologists point out that many of the moral norms commonly accepted
in human societies sanction behaviors also promoted by natural selection
(which promotion becomes apparent only when the inclusive fitness of genes
is taken into account). Examples of such behaviors are the, commandment
to honor one's parents, the incest taboo, the greater blame attributed
to the wife's than to the husband's adultery, the ban or restriction on
divorce, and many others. The sociobiologists' argument is that human
ethical norms are sociocultural correlates of behaviors fostered by biological
evolution. Ethical norms protect such evolution-determined behaviors as
well as being specified by them.
9. Sociobiology's Fallacy
I believe, however, that the sociobiologists' argument is misguided and
does not escape the naturalistic fallacy (see Ayala, 1980, 1982b, 1987,
for more extensive discussion). Consider altruism as an example. Altruism
in the biological sense (altruismb) is defined in terms of the
population genetic consequences of a certain behavior. Altruismb
is explained by the fact that genes prompting such behavior are actually
favored by natural selection (when inclusive fitness is taken into account),
even though the fitness of the behaving individual is decreased. But altruism
in the moral sense (altruismm) is explained in terms of motivations:
a person chooses tc risk his or her own life (or incur some kind of "cost")
for the benefit of someone else. The isomorphism between altruismb
and altruismm is only apparent: an individual's chances are improved
by the behavior of another individual who incurs a risk or cost. The underlying
causations are completely disparate: the ensuing genetic benefits in altruismb;
regard for others in altruismm.
The two disparate meanings of altruism are well distinguished by Ruse
(1986a, 1986b; Ruse and Wilson, 1986; Ruse, Chapter 4), who has become
an ardent proponent of the sociobiologists' thesis concerning the foundations
of ethics. Ruse uses quotation marks ("altruism") to signify
altruism in the biological sense and to differentiate it from moral altruism,
which he writes without the quotation marks. Ruse has articulated perhaps
more clearly than anybody else a sociobiological explanation of the evolution
of the moral sense; namely that the moral sense our proclivity to evaluate
certain actions as good and others as evil--has evolved so that we behave
in ways that improve our fitness, but do not do so in a way that is immediately
obvious. The argument runs as follows. Humans tend to be selfish because
that usually serves best our fitness. Yet, there are situations where
the (inclusive) fitness of our genes is enhanced by cooperation rather
than selfishness; examples are cases of "altruistic" behaviors
similar to those of adult zebras protecting the young in the herd or to
the warning cry of a prairie dog. Natural selection has tricked humans
into exhibiting such (biologically) unobvious beneficial behavior by prompting
us to evaluate such behavior as morally right, which in turn has necessitated
the evolution of the moral sense.
In Ruse's own words, "All such cooperation for personal evolutionary
gain is known technically as 'altruism.' I emphasize that this term is
rooted in metaphor, even timugh now it has the just-given biological meaning.
There is no implication that evolutionary 'altruism' (working together
for biological payoff) is inevitably associated with moral altruism. ...
[Sociobiologists] argue that moral (literal) altruism might be one way
in which biological (metaphorical)'altruism' could be achieved .... Literal,
moral altruism is a major way in which advantageous biological cooperation
is achieved .... In order to achieve 'altruism,' we are altruistic! To
make us cooperate for our biological ends, evolution has filled us full
of thoughts about right and wrong, the need to help our fellows, and so
forth" (Ruse, 1986b, pp. 97-99). Ruse thus provides an explicit interpretation
of Wilson's statement that I have quoted above: "Human behavior...
is the circuitous technique by which human genetic material has been and
will be kept intact. Morality has no other demonstrable ultimate function."
In my view, this justification of the evolution of the moral sense is
misguided. I have argued that we make moral judgments as a consequence
of our eminent intellectual abilities, not as an innate way for achieving
biological gain. I have also argued that the sociobiologists' position
may be interpreted as also requiring that the preferred norms of
morality be those that achieve biological gain (because that is, in their
view, why the moral sense evolved at all). This, in turn, would justify
social attitudes that many of us (sociobiologists included) would judge
morally obtuse and even heinous. Gilkey (Chapter 7) has elaborated on
how even the sociobiologists can and do themselves make moral judgments
that transcend any ethics to which they are entitled by their theories.
They do not seek their own biological gain at all. According to my account
here, those high moral judgments are a consequence of eminent intellectual
abilities. Likewise, Sober (Chapter 6) concludes that, when the human
brain evolves, there are many side effects, in some of which the human
mind attains a selection process of its own, choosing between ideas, deciding
between the better or worse, a selection process that "floats free"
from the determination of natural selection. My way of saying this is
that the norms of ethical systems are to be judged by cultural criteria,
even though natural selection requires us all, as an inevitable byproduct
of our eminent intellectual abilities, to be moral agents.
The discrepancy between biologically determined behaviors and moral norms--which
amounts to a radical flaw in the sociobiologists' argument for a naturalistic
foundation for ethics--is enhanced by three additional considerations
that I shall briefly develop.
The first observation is that our biological nature may predispose us
to accept certain moral precepts, but it does not constrain us to accept
them or to behave according to them. The same eminent intellectual abilities
that make ethical behavior possible and necessary, and in particular free
will, also give us the power to accept some moral norms and to reject
others, independently of any natural inclinations. A natural predisposition
may influence our behavior, but influence and predisposition are not the
same as constraint or determination. It may be, then, that there are natural
dispositions to selfishness (dispositions that Gilkey, Chapter 7, recalls
the theologians have interpreted as original sin). But humans have the
power to rise above these tendencies.
This observation deserves attention because authors such as Konrad Lorenz
(1963) and Robert Ardrey (1966) have presented aggression and the territorial
"imperative" as natural tendencies, which might therefore be
futile to try to resist. Whether or not aggression and the territorial
imperative are ingrained in our genes is neither obvious nor needs to
be explored here. What needs to be said, however, is (1) that the morality
of the behaviors in question is to be assessed in any case by the accepted
norms of morality and not by recourse to biological evidence, and (2)
that if such tendencies or imperatives did exist, people would still have
the possibility and the duty of resisting them (even at the expense of
a fitness reduction) whenever they are seen as immoral (Dobzhansky, 1973).
A second observation is that some norms of morality are consistent with
behaviors prompted by natural selection, but other norms are not so. The
commandment of charity, "Love thy neighbor as thyself," often
runs contrary to the inclusive fitness of the genes, even though it promotes
social cooperation and peace of mind. If the yardstick of morality were
the multiplication of genes, the supreme moral imperative would be to
beget the largest possible number of children and (with lesser dedication)
to encourage our close relatives to do the same. But to impregnate the
most women possible is not, in the view of most people, the highest moral
duty of a man. Rather, the highest moral duties, as judged by cultural
norms, have often been universal duties of justice and benevolence.
The third consideration is that moral norms differ from one culture to
another and even "evolve" from one time to another. Today, many
people see that the Biblical injunction "Be fruitful and multiply"
has been replaced by a moral imperative to limit the number of one's children.
No genetic change in human population accounts for this inversion of moral
value. Moreover, an individual's inclusive fitness is still favored by
having many children.
The evaluation of moral codes or human actions must take into account
biological knowledge, but biology is insufficient for determining which
moral codes are, or should be, accepted. This may be reiterated by returning
to the analogy with syntactic language. Our biological nature determines
the sounds that we can or cannot utter and also constrains human language
in other ways. But a language's syntax and vocabulary are not determined
by our biological nature (otherwise, there could not be a multitude of
tongues), but are products of human culture. Likewise, moral norms are
not determined by biological processes, but by cultural traditions and
principles that are products of human history. That is the difference
of being human.
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