The GOD Delusion (26 page)

Chagnon
is not a supporter of group selection, and nor am I. There are
formidable objections to it. A partisan in the controversy, I must
beware of riding off on my pet steed Tangent, far from the main track
of this book. Some biologists betray a confusion between true group
selection, as in my hypothetical example of the god of battles, and
something else which they
call
group selection but
which turns out on closer inspection to be either kin selection or
reciprocal altruism (see Chapter 6).

Those
of us who belittle group selection admit that in principle it can
happen. The question is whether it amounts to a significant force in
evolution. When it is pitted against selection at lower levels - as
when group selection is advanced as an explanation for individual
self-sacrifice - lower-level selection is likely to be stronger. In our
hypothetical tribe, imagine a single self-interested warrior
in an army dominated by aspiring martyrs eager to die for the tribe and
earn a heavenly reward. He will be only slightly less likely to end up
on the winning side as a result of hanging back in the battle to save
his own skin. The martyrdom of his comrades will benefit him more than
it benefits each one of them on average, because they will be dead. He
is more likely to reproduce than they are, and his genes for refusing
to be martyred are more likely to be reproduced into the next
generation. Hence tendencies towards martyrdom will decline in future
generations.

This
is a simplified toy example, but it illustrates a perennial problem
with group selection. Group-selection theories of individual
self-sacrifice are always vulnerable to subversion from within.
Individual deaths and reproductions occur on a faster timescale and
with greater frequency than group extinctions and fissionings.
Mathematical models can be crafted to come up with special conditions
under which group selection might be evolution-arily powerful. These
special conditions are usually unrealistic in nature, but it can be
argued that religions in human tribal groupings foster just such
otherwise unrealistic special conditions. This is an interesting line
of theory, but I shall not pursue it here except to concede that Darwin
himself, though he was normally a staunch advocate of selection at the
level of the individual organism, came as close as he ever came to
group selectionism in his discussion of human tribes:

When
two tribes of primeval man, living in the same country, came into
competition, if the one tribe included (other circumstances being
equal) a greater number of courageous, sympathetic, and faithful
members, who were always ready to warn each other of danger, to aid and
defend each other, this tribe would without doubt succeed best and
conquer the other . . . Selfish and contentious people will not cohere,
and without coherence nothing can be effected. A tribe possessing the
above qualities in a high degree would spread and be victorious over
other tribes; but in the course of time it would, judging from all past
history, be in turn overcome by some other and still more
highly-endowed tribe.
⁷⁸

To
satisfy any biological specialists who might be reading this, I should
add that Darwin's idea was not strictly group selection, in the true
sense of successful groups spawning daughter groups whose frequency
might be counted in a metapopulation of groups. Rather, Darwin
visualized tribes with altruistically co-operative members spreading
and becoming more numerous in terms of numbers of individuals. Darwin's
model is more like the spread of the grey squirrel in Britain at the
expense of the red: ecological replacement, not true group selection.

In
any case, I want now to set aside group selection and turn to my own
view of the Darwinian survival value of religion. I am one of an
increasing number of biologists who see religion as a
by-product
of something else. More generally, I believe that we who
speculate about Darwinian survival value need to 'think by-product'.
When we ask about the survival value of anything, we may be asking the
wrong question. We need to rewrite the question in a more helpful way.
Perhaps the feature we are interested in (religion in this case)
doesn't have a direct survival value of its own, but is a by-product of
something else that does. I find it helpful to introduce the byproduct
idea with an analogy from my own field of animal behaviour.

Moths
fly into the candle flame, and it doesn't look like an accident. They
go out of their way to make a burnt offering of themselves. We could
label it 'self-immolation behaviour' and, under that provocative name,
wonder how on earth natural selection could favour it. My point is that
we must rewrite the question before we can even attempt an intelligent
answer. It isn't suicide. Apparent suicide emerges as an inadvertent
side-effect or by-product of something else. A by-product of ... what?
Well, here's one possibility, which will serve to make the point.

Artificial
light is a recent arrival on the night scene. Until recently,
the only night lights on view were the moon and the stars. They are at
optical infinity, so rays coming from them are parallel. This fits them
for use as compasses. Insects are known to use celestial objects such
as the sun and the moon to steer accurately in a straight line, and
they can use the same compass, with reversed sign, for returning home
after a foray. The insect nervous system is adept at setting up a
temporary rule of thumb of this kind: 'Steer a course such that the
light rays hit your eye at an angle of 30 degrees.' Since insects have
compound eyes (with straight tubes or light guides radiating out from
the centre of the eye like the spines of a hedgehog), this might amount
in practice to something as simple as keeping the light in one
particular tube or ommatidium.

But
the light compass relies critically on the celestial object being at
optical infinity. If it isn't, the rays are not parallel but diverge
like the spokes of a wheel. A nervous system applying a 30-degree (or
any acute angle) rule of thumb to a nearby candle, as though it were
the moon at optical infinity, will steer the moth, via a spiral
trajectory, into the flame. Draw it out for yourself, using some
particular acute angle such as 30 degrees, and you'll produce an
elegant logarithmic spiral into the candle.

Though
fatal in this particular circumstance, the moth's rule of thumb is
still, on average, a good one because, for a moth, sightings of candles
are rare compared with sightings of the moon. We don't notice the
hundreds of moths that are silently and effectively steering by the
moon or a bright star, or even the glow from a distant city. We see
only moths wheeling into our candle, and we ask the wrong question: Why
are all these moths committing suicide? Instead, we should ask why they
have nervous systems that steer by maintaining a fixed angle to light
rays, a tactic that we notice only where it goes wrong. When the
question is rephrased, the mystery evaporates. It never was right to
call it suicide. It is a misfiring byproduct of a normally useful
compass.

Now,
apply the by-product lesson to religious behaviour in humans. We
observe large numbers of people - in many areas it amounts to 100 per
cent - who hold beliefs that flatly contradict demonstrable scientific
facts as well as rival religions followed by others. People not only
hold these beliefs with passionate certitude, but devote time and
resources to costly activities that flow from holding
them. They die for them, or kill for them. We marvel at this, just as
we marvelled at the 'self-immolation behaviour' of the moths. Baffled,
we ask why. But my point is that we may be asking the wrong question.
The religious behaviour may be a misfiring, an unfortunate by-product
of an underlying psychological propensity which in other circumstances
is, or once was, useful. On this view, the propensity that was
naturally selected in our ancestors was not religion
per se;
it
had some other benefit, and it only incidentally manifests itself as
religious behaviour. We shall understand religious behaviour only after
we have renamed it.

If,
then, religion is a by-product of something else, what is that
something else? What is the counterpart to the moth habit of navigating
by celestial light compasses? What is the primitively advantageous
trait that sometimes misfires to generate religion? I shall offer one
suggestion by way of illustration, but I must stress that it is only an
example of the
kind
of thing I mean, and I shall
come on to parallel suggestions made by others. I am much more wedded
to the general principle that the question should be properly put, and
if necessary rewritten, than I am to any particular answer.

My
specific hypothesis is about children. More than any other species, we
survive by the accumulated experience of previous generations, and that
experience needs to be passed on to children for their protection and
well-being. Theoretically, children might learn from personal
experience not to go too near a cliff edge, not to eat untried red
berries, not to swim in crocodile-infested waters. But, to say the
least, there will be a selective advantage to child brains that possess
the rule of thumb: believe, without question, whatever your grown-ups
tell you. Obey your parents; obey the tribal elders, especially when
they adopt a solemn, minatory tone. Trust your elders without question.
This is a generally valuable rule for a child. But, as with the moths,
it can go wrong.

I
have never forgotten a horrifying sermon, preached in my school chapel
when I was little. Horrifying in retrospect, that is: at the time, my
child brain accepted it in the spirit intended by the preacher. He told
us a story of a squad of soldiers, drilling beside a railway line. At a
critical moment the drill sergeant's attention was distracted, and he
failed to give the order to halt. The soldiers were so
well schooled to obey orders without question that they carried on
marching, right into the path of an oncoming train. Now, of course, I
don't believe the story and I hope the preacher didn't either. But I
believed it when I was nine, because I heard it from an adult in
authority over me. And whether he believed it or not, the preacher
wished us children to admire and model ourselves on the soldiers'
slavish and unquestioning obedience to an order, however preposterous,
from an authority figure. Speaking for myself, I think we
did
admire it. As an adult I find it almost impossible to credit
that my childhood self wondered whether I would have had the courage to
do my duty by marching under the train. But that, for what it is worth,
is how I remember my feelings. The sermon obviously made a deep
impression on me, for I have remembered it and passed it on to you.

To
be fair, I don't think the preacher thought he was serving up a
religious message. It was probably more military than religious, in the
spirit of Tennyson's 'Charge of the Light Brigade', which he may well
have quoted:

'Forward
the Light Brigade!' 

Was there a man
dismayed? 

Not though the
soldiers
knew 

Some one had
blundered: 

Theirs not to make
reply, 

Theirs not to
reason why, 

Theirs but to do and
die: 

Into the valley of
Death 

Rode the
six hundred.

(One
of the earliest and scratchiest recordings of the human voice ever made
is of Lord Tennyson himself reading this poem, and the impression of
hollow declaiming down a long, dark tunnel from the depths of the past
seems eerily appropriate.) From the high command's point of view it
would be madness to allow each individual soldier discretion over
whether or not to obey orders. Nations whose infantrymen act on their
own initiative rather than following orders will tend to lose wars.
From the nation's point of view, this remains a good rule of thumb even
if it sometimes leads to
individual disasters. Soldiers are drilled to become as much like
automata, or computers, as possible.

Computers
do what they are told. They slavishly obey any instructions given in
their own programming language. This is how they do useful things like
word processing and spreadsheet calculations. But, as an inevitable
by-product, they are equally robotic in obeying bad instructions. They
have no way of telling whether an instruction will have a good effect
or a bad. They simply obey, as soldiers are supposed to. It is their
unquestioning obedience that makes computers useful, and exactly the
same thing makes them inescapably vulnerable to infection by software
viruses and worms. A maliciously designed program that says, 'Copy me
and send me to every address that you find on this hard disk' will
simply be obeyed, and then obeyed again by the other computers down the
line to which it is sent, in exponential expansion. It is difficult,
perhaps impossible, to design a computer which is usefully obedient and
at the same time immune to infection.

If I
have done my softening-up work well, you will already have completed my
argument about child brains and religion. Natural selection builds
child brains with a tendency to believe whatever their parents and
tribal elders tell them. Such trusting obedience is valuable for
survival: the analogue of steering by the moon for a moth. But the flip
side of trusting obedience is slavish gullibility. The inevitable
by-product is vulnerability to infection by mind viruses. For excellent
reasons related to Darwinian survival, child brains need to trust
parents, and elders whom parents tell them to trust. An automatic
consequence is that the truster has no way of distinguishing good
advice from bad. The child cannot know that 'Don't paddle in the
crocodile-infested Limpopo' is good advice but 'You must sacrifice a
goat at the time of the full moon, otherwise the rains will fail' is at
best a waste of time and goats. Both admonitions sound equally
trustworthy. Both come from a respected source and are delivered with a
solemn earnestness that commands respect and demands obedience. The
same goes for propositions about the world, about the cosmos, about
morality and about human nature. And, very likely, when the child grows
up and has children of her own, she will naturally pass the whole lot
on to her own children - nonsense as well as sense - using the same
infectious gravitas of manner.