ore clearly in primitive peoples. The
less efficient group is not necessarily exterminated, but if it loses
out in the competition until some other group is able to conquer it and
impose _its_ division of labour the result is of course the extinction
of the conquered group as an integral part of society. This is simply
natural selection working on groups. Natural selection works chiefly in
this manner on the human species, _because that species lives in
groups_. Such group control of the component individuals as has been
described has led to a division of labour between the sexes in every
primitive society. All this means is that the group adopting such a
division has greater survival value, and hence is more likely to be
represented in later ages.

It must not be supposed that such systems of control were always
logically thought out or deliberately planned. Even animals which live
in herds or colonies have divisions of labour.

Through an infinite slaughter of the least fit, such groups arrive at
some kind of instinctive adjustment to produce and protect the young.
The crudest human intelligence must have eliminated much of the waste
involved, by comprehending obvious cause-and-effect relations which
animals have to arrive at through trial and error methods.

For example, an intelligence capable of employing artificial weapons is
also able to see that the wielder of these for group defence cannot be
encumbered with baggage or children when the group is in movement. Hence
women became the burden bearers, and took care of the children, even
after the nursing period. War parties could not generally be mixed, for
the obvious reasons that such women as did not have young children would
be pregnant a good deal of the time, or likely to become so. Moreover, a
hunter and fighter must not have his courage, ferocity and physical
initiative undermined by unsuitable employments and associations.

In a semi-settled group, the hunter and warrior cannot be relied upon to
keep hearth-fires burning or tend crops, even though he may occasionally
have time for such activities. These duties are therefore relegated to
the women, whose child-bearing functions impose upon them a more
sedentary existence. Women must reproduce practically up to their full
capacity to fill up the gaps made by war, accident and disease as well
as death from old age. To this biological service which they alone can
perform are added those which lie nearest it