MARRIAGE SELECTION 



Contribution of Superior People to the Race Much Diminished by Present 



Educational System — Men Must be Made Independent Earlier and 



Women's Colleges Made Co-educational — Motherhood Should 



Receive Greater Honor and Cynical Sex Teachings Be Avoided. 



RoswELL Hill Johnson, 

 Professor of Biology and Geology, University of Pittsburgh, Pittsburgh, Pa. 



THE great principle of natural se- 

 lection still furnishes the chief 

 ^ motive power of evolution, even 

 though nowadays we believe the 

 lines are largely determined by the 

 nature of the variations which appear. 

 Now, in the study of human evolution 

 at least, it becomes necessary to dis- 

 tinguish three distinct kinds of natural 

 selection, for our social agencies affect 

 these three kinds differently. These 

 are lethal selection — that which oper- 

 ates by differential mortality ; sexual se- 

 lection — that which operates by differ- 

 ential success in mating; and fecundal 

 selection — that which operates b\' dif- 

 ferential fecundity. Today it is sexual 

 selection, differential success in mating, 

 that I am to discuss under this title of 

 Marriage Selection. We may call it 

 marriage selection, inasmuch as the 

 extra-marital relations are largely ster- 

 ile, for one reason or another, which we 

 need not here analyze. 



Sexual selection in man has one sharp 

 distinction from that in the inferior 

 si)ecies. In the latter, becau.se of the 

 larger role of instinct and the lesser role 

 of social regulation and judgment, 

 nearly all the individuals mate. There 

 are very few unmated females and very 

 few unmated males, except in species 

 having severe male combat, when mate- 

 lessness is the result of defeat. Where 

 combat prevails, the main result of 

 sexual selection is to cause a disparity of 

 size and strength between the sexes and 

 to accentuate bodily weapons, such as 

 horns, canine teeth, spurs, and the like. 

 Since the disparity of size and 



strength between the .sexes in man is no 

 greater than that in the anthropoid 

 apes, there is no evidence that male 

 combat played a large role in the dawn- 

 man. Indeed, the great reduction in 

 the canine teeth indicates that combat 

 has played a smaller role as time has 

 passed, and fortvmately so. 



COULD NOT OPERATE ALONE. 



Sexual selection in primitive man, as 

 soon as individual combat was reduced, 

 operated very slightly, if unaided. Its 

 effectiveness depended largely upon the 

 co-operation of lethal and fecundal selec- 

 tion. Thus in warfare, the males of the 

 defeated tribes were frequenth' killed, 

 and the females taken as additional 

 wives. Or, even when all eventually 

 mated, some, who possessed a specially 

 desirable characteristic to a higher de- 

 gree, were chosen earlier and thercb}' 

 had more progeny, or they were chosen 

 by the superior, whose progeny would 

 in some cases inherit a greater viability. 



It is very ]jrobable that many of our 

 esthetic attributes, such as musical and 

 artistic ability, which are difficult to 

 account for by lethal selection, have 

 been produced by sexual selection. 



In modem man we have the contrast 

 of an unprecedented number of un- 

 mated individuals. This condition has 

 de\-elo])ed with the growth of romantic 

 love, which is the exclusive ]jreferencc 

 for a \'cr\' long period for one mate 

 over all others. As Finck has ])ointcd 

 out, this has been very much accen- 

 tuated from the time of Petrarch on. 



Now if these unmated individuals 



Address made before the National Conference on Race Betterment, Battle Creek, Mich., 

 January 12, 1914. 



102 



