The new social adjustment of a family, it is probable, is always difficult, and if the change is sudden or extreme, the new environment may rapidly prove fatal to the family. Lorenz (Lehrbuch der Genealogie, p. 135) has shown that when a peasant family reaches an upper social class it dies out in a few generations.

See, on this point, Reibmayr, Entwicklungsgeschichte des Talentes und Genies, Vol. I, ch. vii.