THE SOCIAL FORM OF INFLUENCE. 85 
found in the individual, but the individual must be able to recognize 
those of his own clan, and to keep with them in time of rapid flight. A 
near-sighted deer or cotton-tail rabbit would be in danger of losing his 
life through losing the trail which the leaders have taken, raising their 
tails high that they may be seen by those which follow. 
Social election is a similar principle resting on acquired habits and 
characters. It is due to the necessity for codrdination between the 
social habits of the individual and the social standards of the com- 
munity, in order to secure success and influence. ‘The knowledge of 
a common language is recognized as a fundamental need of a human 
community, and there is a similar need in any community of animals. 
With the lower creatures this need is largely met by inherited instincts, 
which determine the calls and warning cries and the interpretations 
that they receive; but in some cases the training obtained by the 
young from the example of their elders is an important element in the 
transmission of the language. In such cases the standard is main- 
tained by social election. 
It is easy to understand that the red-winged blackbird mentioned 
above, which learned to crow, but had no chance to learn the normal 
song of the species, would not have much influence on the musical 
attainments of the next generation of the species; and perhaps his 
failure in this respect would lessen his influence as a leader in other , 
things. 
One reason for believing that example has no small influence in 
shaping the songs of certain species of birds, is found in the fact that 
Japanese, who highly appreciate the song of the uguisu (sometimes 
called an oriole), are very careful that the young birds that are taken 
from the nests of wild birds in the woods and brought up by hand 
shall have opportunity to hear only the most accomplished adult 
singers during their period of growth. 
Social isolation.—When two groups of a species have been separated 
by geographical barriers for many generations, they are liable to gain 
divergent social habits and instincts, and different calls, rendering 
them unfit for being associated in the same intergenerating group 
when brought into the same district. The geographical isolation has 
ceased, but they continue as separate intergenerating groups through 
the influence of social isolation. 
Social partition.—In so far as the social incompatibilities holding 
two groups apart are due to acquired habits and tend to produce sepa- 
rately associating habitudinal groups, the process may be called 
social partition. 
