therefore, as a fundamental causation unit in desertion. Many
statistical attempts have been made to study the causes of desertion,
and to assign to each its mathematical percentage of influence. The
report of a court of domestic relations gives such an analysis of over
1,500 cases, listing 25 causes, and carefully calculating the percentage
of cases due to each. A summary of these percentages grouped under five
heads is as follows:

_Percentage_
1. Distinct sex factors 39.03
2. Alcohol and narcotic drugs 37.00
3. Temperamental traits 15.40
4. Economic issues 6.27
5. Mental and physical troubles 2.30
------
100.00

It would be easy to criticize the foregoing on the score of grouping.
Can alcoholism and drug addiction be separated from mental and physical
disorders? And how distinguish infallibly between sex factors,
temperamental traits, and mental disabilities? But the main defect in
such statistical studies is that they assume in each case one cause, or
at least one cause sufficiently dominant to dwarf the rest; and few of
the causes listed are really fundamental. The mind instinctively begins
to reach back after the causes of all these causes. The social worker
who made the sweeping assertion that there are two great reasons for
marital discord--"selfishness in men and peevishness in women,"--came a
good deal nearer to an accurate statement of fact with infinitely less
trouble.