Note 99 — Chapter VI · THE ORIGIN OF LAUGHTER.
Reading edition
Champneys and Sigismund are quoted by Preyer. Miss Shinn’s observations are given in her work, Notes on the Development of a Child, p. 238. Mrs. Moore’s are to be found in her Essay, The Mental Development of a Child, p. 37. Dr. L. Hill writes that he noted the first smile in his boy when he was three weeks old, and in his girl when she was some days older.