194 SOCIAL BEHAVIOUR 
attitude, will often throw others into this attitude, though the 
maker of the warning sound may be invisible. That the 
cries of her brood influence the conduct of the hen is a 
matter of familiar observation; and that her danger signal 
causes them at once to crouch or run to her for protection 
is not less familiar. No one who has watched a cat with 
her kittens, or a sheep with her lambs, can doubt that such 
“dumb animals” are influenced in their behaviour by sug- 
gestive sounds. The important questions are, how they 
originate, what is their value, and how far such intercom- 
munication—if such we may call] it—extends. 
There can be but little question that in all cases of animals 
under natural conditions such behaviour has an instinctive 
basis. Though the effect may be to establish a means of com- 
munication, such is not their conscious purpose at the outset. 
They are presumably congenital and hereditary modes of 
emotional expression which serve to evoke responsive behaviour 
in another animal—the reciprocal action being generally in 
its primary origin between mate and mate, between parent 
and offspring, or between members of the same family group. 
And it is this reciprocal action which constitutes it a factor 
in social evolution. Its chief interest in connection with 
the subject of behaviour lies in the fact that it shows the 
instinctive foundations on which intelligent and eventually 
rational modes of intercommunication are built up. For 
instinctive as the sounds are at the outset, by entering into 
the conscious situation and taking their part in the association- 
complex of experience, they become factors in the social life 
as modified and directed by intelligence. To their original 
instinctive value as the outcome of stimuli, and as themselves 
affording stimuli to responsive behaviour, is added a value for 
consciousness in so far as they enter into those guiding situa- 
tions by which intelligent behaviour is determined. And if 
they also serve to evoke, in the reciprocating members of the 
social group, similar or allied emotional states, there is thus 
added a further social bond, inasmuch as there are thus laid 
the foundations of sympathy. 
