E. B. TITCHENER— ETHNOLOGICAL TESTS OF SENSATION. 207 



he was right or wrong, for in default of this precaution many of the subjects 

 soon contented themselves with random answers."^ 



It is a minor but still a relevant detail of criticism that the metal 

 points should have been replaced by hard wood or hard rubber. The 

 metal points appeal to the temperature senses as well as to the sense 

 of pressure. I pass, however, to more important things. It will be 

 noticed that although, on general principles, " the procedure should 

 be, as far as practicable, without knowledge on the part of the sub- 

 ject,"'* the method is in fact full of suggestion. The subject knows 

 what is being done to him; he is to judge whether "one or two 

 points touched his skin." The stimulus-error, with all that it brings 

 in its train, is thus not only admitted but even welcomed. Secondly, 

 the one-point stimuli are " about as frequent " as the two-point. 

 The subject thus has recurring opportunity to check or control his 

 dual judgments. And since he is told " after each answer whether 

 he was right or wrong," the control is continually renewed and the 

 difiference between single and dual stimulation is continually empha- 

 sized. 



The results obtained may be illustrated from the f orearm-limens ;^ 



Murray Islanders. 



Average of 50 men 19.8 mm. (median, 20; extremes, 40 and 2) 



Average of 25 boys 14.0 mm. (median, 15; extremes, 25 and 2) 



Englishmen. 

 Average of 23 men 44.6 mm. (median, 40; extremes, 90 and 10) 



It is clear that the Englishmen have the higher average limen. It 

 is also clear, however, that the range of the results is excessive. 

 In the case of an elementary perceptive discrimination, we do not 

 expect values that range between 40 and 2. or between 90 and 10 

 units of measurement. The results suggest, then, that different 

 subjects may have been doing different things. Fortunately we have 

 collateral evidence which not only confirms the suggestion but also 

 indicates what the different things aimed at and done may have been. 



The limen sought by McDougall was, it will be remembered, " not 



3R, 190 f. 

 4R, 189. 

 5R, 191 f. 



