THE PSYCHOLOGY OF JOKIXG. 327 



THE PSYCHOLOGY OF JOKING. 



By J. HUGHLINGS JACKSON, M.D., F. R. S. 



PUNNING, I think, does not receive enough attention. In spite of 

 Dr. Johnson's well-known dictum, we should not despise pun- 

 ning. Sydney Smith says that it is the foundation of all wit. Supposing 

 three degrees of evolution, I submit that punning is the least evolved 

 system of joking, that wit is evolved out of punning, and that humor 

 is evolved out of wit. Everybody has heard of Sydney Smith's remark 

 — that it requires a surgical operation to get a joke into the head of a 

 Scotchman. But he spoke without distinguishing. The Scotch have 

 a great appreciation of those highly-evolved jocosities displaying the 

 humorous, although, no doubt, a scorn of simj^le, lowly-evolved jocosi- 

 ties, such as plays on words. It is diiEcult to form a conception of a 

 Scotch punster. Yet I have heard an Aberdonian, a physician of world- 

 wide reputation, make a pun. 



Punning is well worthy of the psychologist's attention. I seriously 

 mean that the analysis of puns is a simple way of beginning the me- 

 thodical analysis of the process of normal and abnormal mentation. 

 This, I think, I can easily show. Vision is stereoscopic : in a sense it 

 is slightly diplopic, for there are two dissimilar images, although there 

 seems to be but one external object, as we call it. To borrow the 

 ophthalmological term, we can say that mentation is "stereoscopic" ; 

 always subject-object, although we often speak of it as single ("states 

 of consciousness," etc.). Just as there is visual diplopia, so there is 

 "mental diplopia," or, as it is commonly called, "double conscious- 

 ness." Now I come back to punning. We all have " mental diplopia " 

 when hearing the answer to a riddle which depends on a pun — " When 

 is a little girl not a little girl ? " Answer : " When she is a little horse 

 (hoarse)." The feeble amusement we have in the slightly morbid men- 

 tal state thus induced is from the incongruous elements of a "mental 

 diplopia." The word "hoarse" rouses in us the idea of a little girl 

 who has taken cold, and the same-sounding word " horse " rouses in 

 us the idea of a well-kno\;vTi quadruped at the same time. We have 

 the sensation of complete resemblance M'ith the sense of vast differ- 

 ence. Here is, I submit, a caricature of the normal process of all men- 

 .tation. The process of all thought is "stereoscopic" or "diplopic," 

 being the tracing of relations of likeness and unlikeness. 



To call punning a slightly morbid mental state may be taken as a 

 small joke, but I do not think it very extravagant to describe it so ; it 

 certainly is not if it be a caricature of normal mentation. A miser has 

 been defined as an amateur pauper ; the habitual dmnkard is certainly 

 an amateur lunatic ; and in the same style of speaking we may say 

 that — well, we will say that punning is playing at being foolish ; it is 



