Inherited Habits
Darwin says: “A horse is trained to certain paces, and the colt inherits similar consensual movements.”39 But selection of the constitutional tendency to these paces, and imitation of the mother by the colt, may have been the real causes. The evidence, to be satisfactory, should show that such influences were excluded. Men acquire proficiency in swimming, waltzing, walking, smoking, languages, handicrafts, religious beliefs, &c., but the children only appear to inherit the innate abilities or constitutional proclivities of their parents. Even the songs of birds, including their call-notes, are no more inherited than is language by man (Descent of Man, p. 86). They are learned from the parent. Nestlings which acquire the song of a distinct species, “teach and transmit their new song to their offspring.” If use-inheritance has not fixed the song of birds, why should we suppose that in a single generation it has transmitted a newly-taught method of walking or trotting?
It is alleged that dogs inherit the intelligence acquired by association with man, and that retrievers inherit the effects of their training.40 But selection and imitation are so potent that the additional hypothesis of use-inheritance seems perfectly superfluous. Where intelligence is not highly valued and carefully promoted by selection, the intelligence derivable from association with man does not appear to be inherited. Lap-dogs, for instance, are often remarkably stupid.
Darwin also instances the inheritance of dexterity in seal-catching as a case of use-inheritance.41 But this is amply explained by the ordinary law of heredity. All that is needed is that the son shall inherit the suitable faculties which the father inherited before him.