How many parents will
there be in each group at the end of three generations? If we make no
allowance for the fact that more boys than girls are born, there would
be 136 parents in the two-child group a century hence, and they would
have 136 children. On the other hand, there would be 8744 parents and
21,860 children in the five-child group. Over a hundred and sixty times
as many!

Now that we have done the arithmetic, what does it mean? Of course in
actual life the two-child and the five-child groups will intermarry. And
even if each marries its own kind, the number of children will
fluctuate. Nevertheless, there is plenty of evidence of three great
tendencies. First, certain kinds of families tend to be small or large
as the case may be. Second, each kind tends to marry into its own kind
more often than into the other. And finally, people who grew up in large
families generally like large families and want to have them. Hence the
result of the present limitation of families must be to make large
families and family life in general more popular in the future than at
present.

This is the way it works in the great middle group to which most of us
belong. Families of four to six children are found mainly among people
who love children and are willing to make sacrifices in order to provide
homes for them. So as long as our present limitation of families
continues, the children of each successive generation will tend in
larger and larger numbers to be the descendants of people who believe in
family life and are willing to make sacrifices for it. A few of them are
disappointed because their children do not turn out well, but the great
majority feel well rewarded. Ask parents of three or more children how
they feel about it. Nine out of ten will say that nothing in their lives
has been worth more than their children. So long as people of that kind
have children, and those of the other kind fail to have children, family
life will not die out. It will become more and more the great center of
society. It will change, but the change will be growth, not decay.

Now for the third question, "Is it my duty to marry?" Future generations
may say that the better your physique, the greater your beauty and
strength, the finer your mind, the more lovable your temperament, and
the more highly you are endowed by nature and training, the more
certainly it is your duty to marry and have a family. At present,
however, the answer to "Is it