12 G. V. HAMILTON 



choice been necessary. For example, alley No. 3 was the right 

 alley for the sixteenth trial of any subject, alley No. 2 was the 

 inferentially impossible alley and alleys No. 1, 4 and right alley 

 No. 3 were inferentially possible ones. If a subject tried alley 

 No. 4 first during this trial, then alley No. 1, then (successfully) 

 alley No. 3, a Type A reaction was recorded. But if he tried 

 only alley No. 3 or only alleys No. 4 and 3 his reaction did not 

 enter into any of the tables that deal with the six general reac- 

 tion-types now under discussion. 



The statement that a subject responds with reference to a 

 given rule and the use of such terms as " inferentially possible " 

 and ' ' inferentially impossible ' ' are meant to imply neither aware- 

 ness of rules nor capacity for inference on the part of the sub- 

 jects. In the case of a given subject a few Type A reactions 

 may be manifested during his series of 100 trials, even where 

 an examination of all his reactions may disclose a tendency 

 to favor rather than to avoid the trial-to-trial varying impos- 

 sible alley. 



2. Response to the rule that it is useless to try any alley more 

 than once during a given trial; all four alleys tried, and in an 

 irregular order. 



This is the Type B reaction of the tables. An example of 

 this type would be afforded by a subject if, during his sixteenth 

 trial, he were to try the alleys in the following order: 4, 1, 2, 3; 

 or, 1, 4, 2, 3; or, 2, 1, 4, 3, etc. If this tendency alone were 

 operative during the formal series the subject would have an 

 average chance of effecting his 100 escapes by trying the various 

 alleys 250 times. Since many of the subjects, including the 

 children, were manifestly but little influenced by the one- 

 impossible-alley rule the reaction-type tables omit all reactions 

 in which no alley was entered more than once during a given 

 trial and one or more of the three inferentially possible alleys 

 was not tried, even though the impossible alley was tried. For 

 example, during the sixteenth trial alley No. 3 was the right 

 one and alley No. 2 the impossible one. If the subject tried 

 only alleys No. 1, 2 and 3 or only alleys No. 2 and 3 his reac- 

 tion was not recorded in the tables. These incomplete reac- 

 tions enter, however, into another reckoning of results, as will 

 be seen in subsequent pages. 



