232 SOCIAL BEHAVIOUR 
How, then, can it be said that, “far from being a primitive 
form of organization, the family is a very late product of 
human evolution”? By using the word “family” in a sense 
somewhat different—nay, widely different—from that in which 
it is employed in a biological discussion. In the latter usage 
sexual communism is not excluded ; A., B., and C., D. may have 
offspring this season; A., D., and C., B. next season. In each 
season there are family groups with interchange of partners. This 
does not, however, conform with our conception of the family 
as realized under civilization. Herein, in fact, lies the essential 
difference between the human and the animal family. The 
one is a realized ideal ; the other is merely a natural occurrence. 
Even in the case of monogamous animals, mating for life is 
probably not conduct in conformity with an ideal, but is due 
to the fact that instinctive tendencies have taken this line of 
direction. On the other hand, in monogamous communities of 
mankind, there is, unfortunately, evidence that in some cases 
the ideal is not strong enough to prevent presumably ancestral 
tendencies in the direction of communism. 
The basis of human social conduct is unquestionably to be 
traced in the social behaviour of animals, in inherited tendencies 
to co-operation and mutual help, in the bonds of sympathy 
arising through the satisfaction of impulses towards such 
behaviour, and perhaps, to some extent, in the influence of 
tradition. It is not, however, until this tradition is rendered, 
through descriptive communication, more continuous and more 
effective ; it is not until an ideal of mutual aid, and social 
conduct generally, takes form and is rendered common to the 
tribe; it is not until the more or less realized conceptions of 
one generation are handed on to become the environment 
under which the succeeding generations are nurtured; it is 
not indeed until man consciously and reflectively aims at the 
bettering of his environment in accordance with standards 
rationally conceived and deliberately carried into execution ; 
that a new régime of civilized progress, elsewhere unknown in 
nature, takes definite form. Under this régime, the elimination 
of failures through natural selection, though it may not be 
