Thus we see that the normal mentality of the good branch of the family was able to cope successfully with this intense thirst, while the weakened mentality on the other side was unable to escape, and many fell victims to this appalling habit.
It is such facts as these, taken as we find them, not only in this family but in many of the other families whose records we are soon to publish, that lead us to the conclusion that drunkenness is, to a certain extent at least, the result of feeble-mindedness and that one way to reduce drunkenness is first to determine the mentally defective people, and save them from the environment which would lead them into this abuse.
Again, eight of the descendants of the degenerate Kallikak branch were keepers of houses of ill fame, and that in spite of the fact that they mostly lived in a rural community where such places do not flourish as they do in large cities.
In short, whereas in the Jukes-Edwards comparison we have no sound basis for argument, because the families were utterly different and separate, in the Kallikak family the conclusion seems thoroughly logical. We have, as it were, a natural experiment with a normal branch with which to compare our defective side. We have the one ancestor giving us a line of normal people that shows thoroughly good all the way down the generations, with the exception of the one man who was sexually loose and the two who gave way to the appetite for strong drink.
This is our norm, our standard, our demonstration of what the Kallikak blood is when kept pure, or mingled with blood as good as its own.
Over against this we have the bad side, the blood of the same ancestor contaminated by that of the nameless feeble-minded girl.
From this comparison the conclusion is inevitable that all this degeneracy has come as the result of the defective mentality and bad blood having been brought into the normal family of good blood, first from the nameless feeble-minded girl and later by additional contaminations from other sources.
The biologist could hardly plan and carry out a more rigid experiment or one from which the conclusions would follow more inevitably.