4 JOSEPH PETERSON 



consideration. The most complete response possible, in this 

 sense, — the most consistent — has the advantage and will, other 

 things equal, survive over others. The various tentative begin- 

 nings of acts this way and that, moreover, are not to be regarded 

 as separate acts: they may easily, at a later juncture, be re- 

 solved into the " completest " act. Such conditions, it was 

 maintained, must be taken into consideration to account for 

 the selectiveness manifest in learning. This is a complex 

 "principle" both to state and to test out in experiment; but 

 the organism and the behavior of an animal are inconceivably 

 complex, and over-simplification for the sake of clearness of 

 conception and of explanation is often a positive disadvantage 

 to progress in the biological sciences. Numerous evidences of 

 this statement might be given. 



The experiment reported in the following pages was planned 

 in its main features when the article above referred to was 

 written, and it is there suggested in the concluding paragraph. 

 It was thought that varying the lengths of certain cul de sacs 

 in identical mazes might show a difference in behavior not 

 explicable on the basis of frequency, recency, and intensity of 

 stimulation. If, for instance, a tendency to enter a short cut 

 dc sac is overcome with fewer errors in that particular case, 

 or in fewer runs- through the maze, than are required when the 

 same cul dc sac is lengthened somewhat, it would appear that 

 some other explanation than that based on the principles named 

 is necessar3'\ On the basis of frequency and recency the animal 

 would stand the same chance, on emerging from the blind alley, 

 either of turning back toward the entrance of the maze, on the 

 one hand, or of going toward the food box, on the other, that 

 it would with the blind alley longer. This would certainly be 

 true if acts are the individual and disparate affairs in trial and 

 error processes that they are usually assumed to be, each being 

 co'mplete as a rule before the next is begun. 



Watson says: " This factor (frequency) alone is probably 

 suiTficient to account for the maze habit.. Apparently it is 

 difficult to obtain any explanation based upon other factors. "« 



« Op. cil., pp. 267, 268. In a footnote he says: " If it happens by chance that 

 any cul de sac is entered as frequently as any segment of the true pathway, it becomes 

 as firmly fixed as the true segment." I cannot understand what the warrant is 

 for this statement. A careful tabulation of the detailed movements of some of my 

 rats in the maze shows that it is altogether contrary to the actual facts. In records 



