and strong, and thus family bonds, and ultimately social bonds, are
stronger. In the polygynous household the children of the different
wives are half brothers and half sisters, hence family affection has
little chance to develop among them, and as a matter of fact between
children of different wives there is constant pulling and hauling.
Moreover, because the children in a polygynous family are only half
brothers this immensely complicates relationships, and even the line of
ancestors. Legal relations and all blood relationships are, therefore,
more entangled. It is no inconsiderable social merit of monogamy that it
makes blood relationships simple and usually perfectly definite. All of
this has an effect upon society at large, because the cohesive power of
blood relationship, even in modern societies, is something still worth
taking into account. But of course the main influence of all this is to
be found in the family group itself, because it is only under such
simple and definite relations as we find in the monogamous family that
there is ample stimulus to develop the higher family affections.

(5) From all this it follows that monogamy favors the development of
high types of religion and morals, family affection being an
indispensable root of any high type of ethical religion. That form of
the family which favors the development of the highest type of this
affection will, therefore, favor the development of the highest type of
religion. We see this even more plainly, perhaps, in ancient times than
in the present time, because it was monogamy that favored the
development of ancestor worship through making the line of ancestors
clear and definite, and thus monogamy helped to develop this type of
religion, which became the basis of still higher types.

(6) Monogamy not only favors the preservation of the lives of the
children, but also favors the preservation of the lives of the parents,