BIOLOGY IN HUMAN AFFAIRS 



were laid down by James in his "Principles of Psychology," 

 and to these Thorndike and others have added the law 

 of effect. By the law of use is meant that a mode of response 

 is stamped in by repetition; by the law of disuse, that it 

 tends to fade out when repetitions cease. The law of effect 

 refers to the supposed stamping-in effect of the satisfaction 

 or dissatisfaction which the response brings. 



All of these laws have been called into question by recent 

 investigations. It has been shown that the alleged influence 

 of repetition does not always operate and that mental 

 and psycho-motor functions sometimes continue to improve 

 after practice ceases. As for the law of effect, it is difficult 

 to understand how satisfaction which follows a successful 

 response could operate retroactively to strengthen the 

 bonds which have already acted. The law of trial and error, 

 which alleges that learning to solve problems is typically 

 accomplished by the gradual elimination of unsuccessful 

 responses, at least in the case of animals and young chil- 

 dren, has also been called into question on the basis of 

 experimental data. 



Though the laws of learning which once seemed to have 

 been so definitely established are in dispute, learning 

 nevertheless takes place. The mistake was probably in 

 assuming that the laws were more absolute than they 

 actually are, whereas a given law operates only at times and 

 under certain conditions. As originally formulated and as 

 usually understood, they make learning a more mechanical 

 process than it in fact is, and postulate a neural mechanism 

 far too simple. The investigations of Lashley and Spearman 

 point to the conclusion that in learning the brain does not 

 operate merely as a very complex set of bonds or connec- 

 tions, each serving a specific purpose, but that large areas 

 of the cortex act to a greater or less extent in a unitary 

 manner. The center of attention is shifting from the 

 mechanical aspects of learning to the r61e played by in- 



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