22 (1. V. HAMILTON 



With such marked individual differences to take into account 

 we cannot attach much importance to group averages. Never- 

 theless, the averages given in table 3 are of some interest, as 

 showing that only 2 (Monkey 16 and White Rat 6) of the 28 

 animal subjects from whom complete series were obtained equalled 

 or exceeded the girl-group average of 9.18 Type A reactions per 

 100 trials. 



Table 3 should be directly compared with table 4 since it 

 will suggest that Type B reactions (which involve trying the 

 one impossible alley as well as the three possible ones) may be 

 manifested as an equivalent of Type A reactions in subjects 

 who are capable of learning that it is useless to enter any one 

 alley twice during the same trial. 



It is not to be forgotten that even a few Type A reactions 

 may express a feebly potent tendency to avoid the varying 

 impossible alley. On the other hand a reaction of this type 

 may be accidental in the sense that failure to try the impossible 

 alley may be due to the operation of other tendencies than 

 that which would lead to an avoidance of it. E.g., if a subject 

 stereotypes a method of initiating all trials by first entering 

 alley No. 1 and of following this activity by entering, wherever 

 it is necessary, the other alleys in the order of their occurrence 

 from left to right until the right one is found he will necessarily 

 manifest an equal number of Type A and Type C reactions. 

 The same will obtain if he adopts the reverse method, i.e., if 

 he initiates each trial by entering alley No. 4 and working from 

 right to left in search of the right alley. 



TABLE 3 TABLE 4 



Average number Average number 



A-reactions B-reactions 



Group per 100 trials per 100 trials 



Girls (incomplete records excluded) 9. 18 1 . 24 



Girls (feeble-minded cases excluded) .... 10. 29 1 . 00 



Baboon and Monkeys 6. 40 6. 00 



(atypical Monkeys 5 and 26 excluded) . . 8.33 6.67 



Mouse 4.00 7.00 



Gray Rats 2.80 5.20 



Black Rats ^ 6.2.5 2.50 



WhiteRats . 6.38 2.25 



Gophers 3.80 1.20 



