40 Heredity and Social Progress 



activity is the main element in the emotion 

 that follows the unexpected discharge of sur- 

 plus energy. 



The voluntary muscles are not strongly 

 affected by emotions. The will has a firm 

 control over them, and hence they are to a less 

 degree the channels along which the unex- 

 pected output of energy goes. If they are 

 affected, it is by some sympathetic movement 

 outside of conscious control causing a combi- 

 nation of movements not in harmony with the 

 regular activity of the muscles involved. Her- 

 bert Spencer asserts that emotion affects the 

 muscles in an inverse ratio to their mass and 

 to the weight of the parts they have to move. 1 

 They act first on the muscles of the voice and 

 face, and gradually extend to the arms, legs, and 

 body. Mantegazza 2 says they begin in the 

 face and extend to the neck, arms, hands, 

 trunk, and lower limbs. These statements 

 express the general fact that the voluntary 

 muscles, being most under the control of the 

 will, are least affected and come under the 



1 "Principles of Psychology," Vol. II., p. 542. 



2 " Physiognomy and Expression," p. 258. 



