Chap. VIII. LAUGHTER. 197 



clapped her hands, and the colour mounted to her 

 cheeks." On other occasions she has been seen to stamp 

 for joy. 2 



Idiots and imbecile persons likewise afford good evi- 

 dence that laughter or smiling primarily expresses mere 

 happiness or joy. Dr. Crichton Browne, to whom, as 

 on so many other occasions, I am indebted for the results 

 of his wide experience, informs me that with idiots 

 laughter is the most prevalent and frequent of all the 

 emotional expressions. Many idiots are morose, pas- 

 sionate, restless, in a painful state of mind, or utterly 

 stolid, and these never laugh. Others frequently laugh 

 in a quite senseless manner. Thus an idiot boy, incapa- 

 ble of speech, complained to Dr. Browne, by the aid of 

 signs, that another boy in the asylum had given him 

 a black eye; and this was accompanied by " explosions 

 of laughter and with his face covered with the broadest 

 smiles." There is another large class of idiots who are 

 persistently joyous and benign, and who are constantly 

 laughing or smiling. 3 Their countenances often exhibit 

 a stereotyped smile; their joyousness is increased, and 

 they grin, chuckle, or giggle, whenever food is placed 

 before them, or when they are caressed, are shown bright 

 colours, or hear music. Some of them laugh more than 

 usual when they walk about, or attempt any muscular 

 exertion. The joyousness of most of these idiots cannot 

 possibly be associated, as Dr. Browne remarks, with any 

 distinct ideas: they simply feel pleasure, and express 

 it by laughter or smiles. With imbeciles rather higher 

 in the scale, personal vanity seems to be the commonest 

 cause of laughter, and next to this, pleasure arising from 

 the approbation of their conduct. 



2 F. Lieber on the vocal sounds of L. Bridg-man, ' Smith- 

 sonian Contributions,' 1851, vol. ii. p. 6. 



8 See, also, Mr. Marshall, in Phil. Transact. 1864, p. 526. 



