Continued ill health of the wife brings burdens, financial and other,
which may help through discouragement to break down the husband's
morale.

There should be included here some consideration of one of the most
puzzling types of abandonment--the "pregnancy desertion." Attempts have
been made to explain it on the ground of the instinctive aversion of the
male sex for domestic crises. But the impulse that causes the
prosperous householder to move to his club when house-cleaning time
arrives will hardly serve to explain such a custom, and as a matter of
fact other domestic crises, such as illnesses of the children, do not
have any such effect upon the man who habitually absents himself from
home before the birth of each child. Other possible reasons for it are
the well-known irritability and "difficulty" of women in this condition,
and their aversion to sexual intercourse. Some pregnancy deserters take
the step in the hope that their wives will bring about an abortion; but
this is a modern and sophisticated development and the institution of
"pregnancy desertion" is one of undoubted antiquity. Its prevalence
among certain European immigrants would almost point to its being a
racial tradition. Ethnologists who have studied strange marriage
customs, such as the "couvade," ought to turn their attention to
discovering the causes of this other and socially more important marital
vagary.

10. Temperamental Incompatibility.--It is difficult to catalogue and
appraise the causal factors in desertion that lie in personality. They
are closely related to differences in background and are intimately
involved with the sex relations of the pair. We cannot, however, admit
that they are identical with the latter, as some students of the subject
claim; or that the only incompatibility in marriage is sex