ON LAUGHTER"^ 



By Arthur Allin 



' So far as ticklishness is concerned, a very important factor in the 

 production of this feeling is undoubtedly that of the summation of 

 stimuli. In a research of Stirling's carried on under Ludwig's direc- 

 tion (-> it was shown that reflex contractions only occur from repeated 

 shocks to the nerve centers — that is, through summation of succes- 

 sive stimuli. 



That this result is also due in some degree to an alternating 

 increase in the sensibility of the various areas in question from 

 altered supply of blood is reasonably certain. The connection of 

 tickling with capillary pulsation is therefore worthy of investigation. 

 As a consequence of this summation -process there could result in 

 many cases and in cases of excessive nervous discharge the opposite 

 of pleasure, namely, pain. This would result from long-continued 

 stimulation or from light stimulation whenever the central nerve 

 cells were possessed of little stability or inhibitory capacity, as in 

 sickness, etc. A number of instances have been recorded of death 

 resulting from tickling and there is no reason to doubt the truth of 

 the statement that Simon de Montfort, during the persecution of the 

 Albigenses, put some of them to death by tickling the soles of their 

 feet with a feather. Mediaeval Justice and the hidden doings of the 

 Inquisition might reveal many such instances if they were investi- 

 gated. Lauder Brunton suggests that possibly the different effect of 

 a slight stimulus like the touch of a feather, which causes intense 

 reflex action, and of a gentle but steady pressure of the tinger, which 

 gives rise to no reflex action at all, may be due to the stimulation by 

 the latter of two sets of nerves which counteract or inhibit each 



(1) Reprinted from The Psychological Review, Vol. X, No. 3, May, 1903. 



(2) Stirline:. Ludwig's Arbeiten, 9ter Jahrerane, p. 290; Sitz. Ber. d. k. Sach. Gesell. d. ^Viss., 



Bd. XXVI.. p. 439. 



