184 SECTIONAL ADDRESSES. 



What are the facts ? Here no ordinary observations of what may be 

 occasional coincidences is enough. Observations, indeed, of the first 

 twelve months did quite convince me that primary purposeless imitations 

 are constantly taking place ; but to make sure I planned two series, of 

 about fifty tests in all, on my little girl (Y) of twelve months. The actions 

 done in front of her, usually by myself or her mother, were all of a type we 

 thought she could perform ; but we and others tried to think of actions 

 she would not be likely to do, and they were included in the tests. Yet 

 in the first series at twelve months, of thirty-seven tests there was imitation 

 in thirty-one, and in the six failures there was, with one exception, a good 

 reason for non-imitation, as that the child was playing with a toy, or that 

 the action, like shaking the head, had come to mean something to the 

 child, which she did not mean at the moment. 



The actions included many which could not possibly be ' under- 

 stood,' and which served no ulterior purpose, e.g. puffing as though 

 smoking, opening the mouth wide, airing a garment by the fire, and various 

 physical exercises. 



A similar proportion of actions was imitated in a series of twenty-eight 

 tests at two years of age. Y may have been exceptionally imitative. But a 

 colleague who is thoroughly familiar with the methods and difficulties 

 of experimental psychology gave his boy the same tests at twenty-two 

 months, and found almost identical results. 



It would take far too long to expound fully the psychology of imitation 

 suggested by these observations and experiments, but I may mention one 

 incident which gives, I believe, a clue to primary imitation in infancy. To 

 see if a very simple action was imitated at twelve months I held my mouth 

 open wide in front of my daughter Y. She showed signs of great annoy- 

 ance, banging her hand to and fro at my mouth. Then her own mouth 

 opened wide. Again when I opened my mouth she showed dislike, and 

 even a suggestion of fear, and crawled away from me, but as she came round 

 the back of a chair I noticed that she was crawling along with her mouth 

 held wide open. 



No one formula, I think, can cover all types of imitation at this stage : 

 but there does reveal itself a general tendency to imitate actions which 

 engross the attention for the moment, in the absence of competing sources 

 of interest. 



Another problem of general psychology, on which the study of infancy 

 throws a light, is that of the causes of Laughter, as to which such varied 

 theories have been held. 



Those theories of laughter which are based on a study of wit and 

 humour, fail to allow for the very basic origins of laughter. Again, theories 

 have generally erred in being far too simple. The careful observation of 

 the earliest occasions of laughter suggest that the causes are very varied. 

 I give here the various causes in the order in which they appeared in the 

 case of my boy B. 



(i) The first clear laugh I noted in my children was that of B (whom 

 I watched especially for laughter development) at the age of thirty-nine 

 days — a laugh of delight at being put into position to take food. Several 

 other observations showed that the getting of food or anticipation of it 

 was the earliest cause of laughter, as Dearborn also noted in his daughter. 



