82 TABOO AND GENETICS 



work somewhat differently in the presence of 

 unlike blood streams. As to the greater average 

 weight of the male brain, this is true of the whole 

 body. Brain weight, either absolute or relative 

 to body weight, is not positively known to be 

 in any way correlated (in normal people) with 

 mental capacity. 



A library might be stocked with the vast 

 literature devoted to summarizing and cata- 

 loguing sex differences ; and most of it would 

 be useless from the standpoint of sociology. 

 Unaccompanied by the criticisms a biologist 

 would have to make on the method of their 

 ascertainment and validity, not to mention their 

 significance, such lists can easily do — and prob- 

 ably have done — more harm than good. One 

 simple and reasonable criterion would reduce 

 this catalogue to fairly modest proportions, so 

 far as social science is concerned : Which ones 

 have an obvious or even probable social signi- 

 ficance ? Over and above that, while such con- 

 trasts may be of speculative interest, they lead 

 imaginative people to argue from them by 

 analogy and thus cloud the real issues. 



What are the outstandingly significant sex 

 differences which application of the above 

 criterion leaves ? (i) A less active and more 

 uneven metabolism of woman ; (2) Associated 

 with this, less physical strength on the average 

 — hence an inferior adaptability to some kinds 



