INSTINCT. 59 



activities : swimming to shore when thrown into the water, 

 fighting (observed as early as the sixth day), appropriate reac- 

 tions to distance in jumping down from heights, avoidance of 

 open places, reacting to honey-bees by seizing, knocking them 

 against the ground, and then eating them (see Psychological 

 Review, May, 1899). 



Turning to our proper task, the statement of some character- 

 istics of instinctive activities in general, we should first recall 

 the familiar fact that to say that a certain ability or tendency 

 is in an animal apart from teaching or experience, is born in 

 him, is not to say that at birth he possesses it or that all 

 through life he keeps it. Scratching the ground in the case of 

 the chick, walking in the case of the human infant, are obvious 

 examples of true instincts which yet do not appear for some 

 time after birth. The instinct to follow and the instinctive 

 avoidance of loneliness which the chick manifests so markedly 

 in the earliest days of his life disappear to a large extent if 

 given no chance to harden into habits. Instincts, that is, may 

 be delayed 2X& may be transitory. Care must always be taken 

 by the student, however, not to interpret as delayed instincts 

 cases where the reason for delayed activity is really lack of 

 strength in some organ, or as transitory instincts cases where 

 the reason for loss of the activity is loss of strength or inhibi- 

 tion of the activity by unpleasant consequences. 



Perhaps the most important general statement one can make 

 about instinctive reactions is that they are often indefinite and 

 inexact. The same situation may be reacted to differently by 

 different individuals of a species, or by the same individual on 

 different occasions. The Peckhams (Wisconsin Geological 

 Survey, Bulletin No. 2) have shown decisively this inexact- 

 ness, this vagueness of reaction in the case of the nest-building 

 and stinging habits of the solitary wasps. Among vertebrates 

 one sees it almost everywhere. If you slam a door in a room 

 where you have half a dozen chicks, one may run and crouch 

 for twenty seconds, another may squat where he is for an equal 

 time, another may also chirp, while the others may keep on 

 feeding undisturbed. The old theory of instinct, that it was a 

 sort of God-given power bestowed on animals to make up for 



