12.6 



THE QUARTERLY REVIEW OF BIOLOGY 



We have devoted the bulk of this review- 

 to a consideration of the basic doctrine, 

 and very little space is left for an exposi- 

 tion of the remainder of the book — 

 which bulks rather larger than the portion 

 we have examined. In the rest of the book 

 Spearman builds his theory into an impos- 

 ing edifice. This construction, however, 

 rests entirely on the fundamental proposi- 

 tion that the decomposition of abilities 

 into g and s is really valid. There are, 

 however, some interesting results ob- 

 tained. In particular, he devotes a good 

 deal of attention to the search for general 

 factors other than g common to numerous 

 abilities. He claims to find such a factor 

 (which he calls w) in the "consistency of 

 action resulting from volition;" and he 

 finds another factor, called c, whose pre- 

 cise nature is not quite clear, but which 

 presents some interesting correlations with 

 various traits of character. A selection 

 of these (quoted from page 355) follows: 



Sense of humor 0.98 



Pure-mindedness — 0.45 



Originality of ideas 0.88 



Interest in religion — o . 39 



Suggestibility —0.2.9 



Profoundness of apprehension o . 59 



In conclusion, we may say that Pro- 

 fessor Spearman seems to us to have fallen I 

 a long way short of establishing his theory. 

 On the other hand, he has made out enough^ 

 of a case to call for the serious considera- ' 

 tion and investigation which his book will ] 

 undoubtedly receive. 



[The current issue of Biometrika (Dec. \ 

 19x7, pp. 146-191) which appeared while 

 this review was going through the press, 

 contains a long analysis and criticism, , 

 by Pearson and Moul, of Professor Spear- I 

 man's mathematics. The conclusion is 

 there reached that the tests provided by 

 Spearman are mathematically entirely ' 

 inadequate to establish his theory; andi 

 in particular, that his formula for thel 

 standard deviation of a tetrad difference j 

 is in error. Accordingly, some of the 1 

 statements made above may require quali- 

 fication; but the conclusions reached ; 

 still seem sound.] 



