Darwin's Dangerous Idea - Evolution and the Meaning of Life

478 ON THE ORIGIN OF MORALITY
under many but not all circumstances, evolve. ( Remember that only some
species engage in parental investment. This is not an option for species in
which the young hatch after the parents have died, and the reasons why there
should be these fundamentally different parental policies have been well
investigated. 7 ) Now, once parental investment in their own offspring is
secured for a species, how do we expand the circle (Singer 1981)? It is just
as uncontroversial, thanks to Hamilton's pioneering work (1964) on "kin
selection" and "inclusive fitness," that the same considerations that favor
sacrifices for one's offspring also favor, to a mathematically precise degree,
sacrifices for one's more distant relatives: offspring aiding parents, siblings
helping each other, aunts helping nephews, and so forth. But, again, it is
important to remember that the conditions under which such aid is evolutionarily
enforceable are not only not universal but relatively rare.
As George Williams (1988) notes, not only is cannibalism (eating conspecifics,
even close relatives) common, but in many species sibling-cide
(we won't call it murder, since they know not what they do ) is almost the
rule, not the exception. (For instance, when two or more eagle chicks are
born in a single nest, the first to hatch is very likely to kill its younger
siblings if it can, by pushing the eggs out of the nest, or even pushing the
hatchlings out.) When a lion acquires a new lioness who is still nursing cubs
from an earlier mating, the first order of business is to kill those cubs, so that
the lioness will more quickly come into estrus. Chimpanzees have been
known to engage in mortal combat against their own kind, and langurmonkey
males often kill the infants of other males to gain reproductive
access to females (Hrdy 1977)—so even our closest relatives engage in
horrible behavior. Williams points out that, in all the mammalian species that
have so far been carefully studied, the rate at which their members engage in
the killing of conspecifics is several thousand times greater than the highest
homicide rate measured in any American city. 8
This dark message about our furry friends is often resisted, and popular
presentations of nature (in television documentaries, magazine articles, and
popular books ) often engage in self-censorship to avoid shocking the squeamish.
Hobbes was right: life in the state of nature is nasty, brutish, and short,
for virtually all nonhuman species. If "doing what comes naturally" meant
doing what virtually all other animal species do, it would be hazardous to the
health and well-being of us all. Einstein famously said that the dear God
7. Complications abound, as usual. In some species of beetle, for instance, the males make
a huge investment in a food plug (with sperm attached) that females compete for. This
is a sort of parental investment, but not the sort we are discussing here.
8. Gould draws attention to the same striking statistic in "A Thousand Acts of Kindness,"
in Gould 1993d.
Some Varieties of Greedy Ethical Reductionism 479
is subtle but not malicious; Williams turns that observation inside out:
Mother Nature is heartless—even vicious—but boundlessly stupid. And as
so often before, Nietzsche finds the point and gives it his special touch:
"According to nature" you want to live? O you noble Stoics, what deceptive
words these are! Imagine a being like nature, wasteful beyond measure
indifferent beyond measure, without purposes and consideration,
without mercy and justice, fertile and desolate and uncertain at the same
rime- imagine indifference itself as a power—how could you live according
to this indifference! [Nietzsche 1885, p. 15]
Beyond inclusive fitness comes "reciprocal altruism" (Trivers 1971), in
which nonrelated or distantly related organisms—they needn't even be of the
same species—can form mutually beneficial arrangements of quid pro quo,
the first step towards human promise-keeping. It is commonly "objected"
that reciprocal altruism is ill-named, since it isn't really altruism at all, just
enlightened self-interest of one form or another: you scratch my back and I'll
scratch yours—quite literally, in the case of the grooming arrangements that
are a favorite simple example. This "objection" misses the point that we have
to pass by small steps to the real McCoy, and reciprocal altruism, ignoble (or
just a-noble) as it may be, is a useful stepping-stone on the progression. It
requires advanced cognitive abilities—a rather specific memory capable of
reidentifying one's debtors and creditors, and the capacity to spot a cheat, for
instance.
Moving beyond the most businesslike and brutal forms of reciprocal
altruism towards a world in which genuine trust and sacrifice are possible is
a task that has begun to be explored theoretically. The first major step was
Robert Axelrod's (Axelrod and Hamilton 1981, Axelrod 1984) Prisoner's
Dilemma tournaments, which invited all comers to submit strategies—algorithms—for
competing against all comers in a reiterated Prisoner's Dilemma
tournament. (Among the many discussions of this topic, two of the
best are Dawkins 1989a, ch. 12, and Poundstone 1992.) The winning strategy
became justly famous: Tit for Tat, which simply copies the "opponent's"
previous move, cooperating in reward for past cooperation, and defecting in
retaliation against any defections. Basic Tit for Tat comes in a variety of
subspecies. In Nice Tit for Tat, one begins by cooperating, and then just does
unto the other as the other has done unto oneself on the previous move. As
can be readily seen, two Nice Tit-for-Tatters playing opposite one another
make out splendidly, cooperating indefinitely, but a Nice Tit-for-Tatter who
encounters a Nasty Tit-for-Tatter who throws in an unprovoked defection at
any point is in for a debilitating round of endless retaliatory defection (it
serves them both right, of course, as they keep reminding themselves).