On the Different Forms of Acquiring Knowledge. 157 



instinctive imitation. When any member of a social 

 gathering chances to yawn, his action is "spontane- 

 ously," or, may be, reflexively imitated by those who 

 see it. The perception of his motion actuates a similar 

 reflex activity on their part. The simplest instinctive 

 imitations of animals may be explained in this manner. 

 The psychic element of sight perception serves as the 

 releasing moment. The less, however, the activity 

 which is imitated be purely reflex, as it is in yawning, 

 the more will psychic elements participate in the imita- 

 tion. Hence we are fully justified in speaking of 

 "learning by imitation." 



It may be anticipated that this form of learning is 

 prominent in animals of social habits. We find, in- 

 deed, many instances of it in ant life. The above men- 

 tioned attacks upon the Dinarda, that occurred in the 

 nests I had under observation, and especially in one 

 large nest 1 of Formica sanguinea, in which several 

 kinds of slaves were kept, clearly manifests the in- 

 fluence of this instinct of imitation. When one or a 

 few ants commenced to pursue the Dinarda which met 

 them, their example soon proved so catching, that many 

 of the others, masters as well as slaves, that had not 

 happened to meet the unfortunate beetle, or had even 

 previously ignored it, began to hustle and search for the 

 intruder. 2 



This mode of learning by imitation can be still better 

 observed, when ant colonies and particularly mixed col- 

 onies of Formica sanguinea receive genuine guests into 



*) A cut of which is given in the "Vergleichende Studien" (1. 

 Aufl., p. 15). 



2 ) See "Die psychischen Faehkeiten der Ameisen," p. 93 ff. 



