One serious drawback in making a study of the inheritability of insanity and other nervous disorders is that so far we have dealt mainly with mass effects rather than specific neuroses.
Unquestionably in cases of imbecility it is easier than in insanities to pass conclusive judgment on the inheritability of the condition in a large class of cases.
In general there is more doubt about the inheritability of some of the insanities than about cases of mental deficiency.
But now the inheritability of powers acquired by the individual through his own efforts, is disputed; and, if the denial be made good, all such explanations as the above must be revised.
Of the strong inheritability of idiocy there can be no doubt.
Learn how to estimate the inheritability of such traits in a family line, upon specific mating with another family line.
In calculating the inheritability of traits, it is also necessary to consider that certain physical, mental and moral traits flower at the arrival of certain ages only.
An appreciation of what is feeble-minded, and a realization of its inheritability can not help but modify a man or a woman's admiration for the traits or lack of traits which it embraces.
These are suggestive of the inheritability of many other mental traits not yet studied.
