42 Heredity and Social Progress 



portion follows and the organism is modified to 

 meet the situation. 



This arrest of development seems to me to 

 be the most important fact relative to the emo- 

 tions. If the primary effect of emotion is to 

 dwarf structure, it is perhaps the sole cause of 

 the change in organisms when under the stress 

 of struggle. The principle of natural selection 

 assumes that struggle causes starvation and 

 disease whereby the weak are eliminated. If 

 emotion dwarfs and arrests development, the 

 same effects could be brought about much 

 more readily and quickly by it than by natural 

 selection. The dwarfed parts would give new 

 proportions to the body and make it less fit for 

 the existing environment ; but by a movement 

 to a new environment, a place could be found 

 where the new qualities and functions would 

 be useful. Emotion thus injures the static, 

 but aids those mobile enough to seek new sit- 

 uations where the new combination of quali- 

 ties are sources of strength. When deer are 

 attacked by lions, if some were killed the elimi- 

 nation would create change through natural 

 selection. But the emotion caused by the 



