THE STUDY OF SOCIOLOGY.
V. Objective Difficulties (continued).
ANOTHER common cause of very serious perversion of evidence is the unconscious confounding of observation with inference. Everywhere, a fertile source of error is the putting down as something perceived what is really a conclusion drawn from something perceived; and this is a more than usually fertile source of error in Sociology. Here is an instance:
A few years ago Dr. Stark published the results of comparisons he had made between the rates of mortality among the married and among the celibate; showing, as it seemed, the greater healthfulness of married life. Some criticisms made upon his argument did not seriously shake it; and he has been since referred to as having conclusively proved the alleged relation. More recently I have seen quoted from the Medical Press and Circular the following summary of results supposed to tell the same tale:
"M. Bertillon has made a communication on this subject (the Influence of Marriage) to the Brussels Academy of Medicine, which has been published in the Revue Scientifique. From 25 to 30 years of age the mortality per 1,000 in France amounts to 6.2 in married men, 10.2 in bachelors, and 21.8 in widows. In Brussels the mortality of married women is 9 per 1,000, girls the same, and widows as high as 16.9. In Belgium, from 7 per 1,000 among married men, the number rises to 8.5 in bachelors and 24.6 in widows. The proportion is the same in Holland. From 8.2 in married men, it rises to 11.7 in bachelors, and 16.9 in widowers, or 12.8 among married women, 8.5 in spinsters, and 13.8 in widows. The result of all the calculations is that from 25 to 30 years of age the mortality per 1,000 is 4 in married men, 10.4 in bachelors, and 22 in widowers. This beneficial influence of marriage is manifested at all ages, being always more strongly marked in men than in women."