Key, Dr. Wilhelmina E., Feeble-minded Citizens in Pennsylvania, pp. 11, 12, Philadelphia, Public Charities Assn., 1915.

The most recent extensive study of this point is A. H. Estabrook's The Jukes in 1915 (Carnegie Institution of Washington, 1916). The Jukes migrated from their original home, in the mountains of New York, a generation ago, and are now scattered all over the country. Estabrook tried to learn, at first hand, whether they had improved as the result of new environments, and free from the handicap of their name, which for their new neighbors had no bad associations. In general, his findings seem to warrant the conclusion that a changed environment in itself was of little benefit. Such improvement as occurred in the tribe was rather due to marriage with better stock; marriages of this kind were made more possible by the new environment, but the tendency to assortative mating restricted them. It is further to be noted that while such marriages may be good for the Juke family, they are bad for the nation as a whole, because they tend to scatter anti-social traits.