The elimination of thoughtless cruelty is to be effected most easily by developing an interest in construction and growth. Almost every child, as soon as he is old enough, wants to kill flies and other insects ; this leads on to the killing of larger animals, and ultimately of men. In the ordinary English upper-class family, the killing of birds is considered highly creditable, and the killing of men in war is regarded as the noblest of professions. This attitude is in accordance with untrained instinct : it is that of men who possess no form of constructive skill, and are therefore unable to find any innocent embodiment of their will to power.
Sopurce: On Education, especially in early childhood, 1926, Pt. 2： Education of character, chap. 6: Constructiveness. More info.:http://russell-j.com/beginner/OE06-040.HTM