SOME PRINCIPLES OF A BIOLOGICAL PSYCHOLOGY.
Man and a certain number of other species widely distributed throughout the animal kingdom show, in addition to the instincts of self-preservation, nutrition, and sex, specialized inherited modes of response to the needs, not directly of the individual but of the herd to which he belongs. These responses, which are perfectly well marked and characteristic, are those of the herd instinct. It is {98} important to grasp clearly the relation of this instinct to the individual. It must be understood that each separate member of a gregarious species inherits characters deeply rooted in his being which effectually differentiate him from any non-gregarious animal. These characters are such that in presence of certain stimuli they will ensure his responding in a specialized way which will be quite different from the response of a solitary animal. The response when examined will be found not necessarily to favour the survival of the individual as such, but to favour his survival as a member of a herd. A very simple example will make this plain. The dog and the cat are our two most familiar examples of the social and the solitary animal respectively. Their different attitudes towards feeding must have been observed by all. The cat takes her food leisurely, without great appearance of appetite and in small amounts at a time; the dog is voracious and will eat hurriedly as much as he can get, growling anxiously if he is approached. In doing so he is expressing a deeply ingrained characteristic.