24 HEREDITY AND SOCIAL FITNESS 



Summary of Line A. 



Line A shows considerable diversity as to the strains into which 

 its members marry. Union of its founder with a woman who was 

 fairly able mentally but aggressive in evil and sexually lax, and be- 

 longed to a neurotic strain, produces a very diverse family whose 

 differences are further accentuated b}^ environmental influences. 

 Their mentally deficient sexually immoral daughter mating with a 

 sexually loose man had children showing lack of sex control in the pro- 

 portion of 2 out of 3. Later unions of these with members of strains 

 showing superior ability to plan and calculate bring about advance so 

 far as these traits are concerned but a persistence in the lack of sex 

 control. The two members of generation III who were superior in cal- 

 culating ability and perseverance but still low in aggressiveness mar- 

 ried into strains showing at least an average of these traits, and the 

 condition of subsequent generations with reference to these traits is 

 considerably improved, except where the sole defective daughter, 

 through marriage into a weak strain, carries on the line for deficiency 

 in calculating ability and perseverance. The remaining members of 

 this line show a good average of social efficiency considerably above the 

 condition of the family three generations ago; while in several cases 

 the combination of mechanical ability and special calculating ability 

 with aggressiveness is bringing the individual possessing the fortunate 

 combination marked success. 



