It may come as a surprise to pediatricians that Charles Darwin (1802-1882) had a significant influence on child psychology. The observations he made on the development of his first son that were published in an article in Mind in July 1877 are republished here. This article is testimony to his broad interest and his skill as an observer. However, it is not this article alone that influenced child psychology but also the major publications that preceded it, The Origin of the Species, The Descent of Man, and The Expression of Emotions in Man and Animals.
These books supported scientifically the idea of the perfectibility of man and made the study of man a scientific subject. Interest was stimulated in comparisons of animal behaviors with behaviors of the child. The concept that ontogeny recapitulated phylogeny was extended from organ systems to behavior, and the child became a source of scientific information
Marian Sigman, Arthur H. Parmelee. Child Psychology, 1877. Am J Dis Child. 1977;131(8):908. doi:10.1001/archpedi.1977.02120210086018