Slightly more complex manifestations of the same tendency to homogeneity are seen in the desire for identification with the herd in matters of opinion. {32} Here we find the biological explanation of the ineradicable impulse mankind has always displayed towards segregation into classes. Each one of us in his opinions and his conduct, in matters of dress, amusement, religion, and politics, is compelled to obtain the support of a class, of a herd within the herd. The most eccentric in opinion or conduct is, we may be sure, supported by the agreement of a class, the smallness of which accounts for his apparent eccentricity, and the preciousness of which accounts for his fortitude in defying general opinion. Again, anything which tends to emphasize difference from the herd is unpleasant. In the individual mind there will be an unanalysable dislike of the novel in action or thought. It will be “wrong,” “wicked,” “foolish,” “undesirable,” or as we say “bad form,” according to varying circumstances which we can already to some extent define.
Manifestations relatively more simple are shown in the dislike of being conspicuous, in shyness and in stage fright. It is, however, sensitiveness to the behaviour of the herd which has the most important effects upon the structure of the mind of the gregarious animal. This sensitiveness is closely associated with the suggestibility of the gregarious animal, and therefore with that of man. The effect of it will clearly be to make acceptable those suggestions which come from the herd, and those only. It is of especial importance to note that this suggestibility is not general, and that it is only herd suggestions which are rendered acceptable by the action of instinct. Man is, for example, notoriously insensitive to the suggestions of experience. The history of what is rather grandiosely called human progress everywhere illustrates this. If we look back upon the development of some such thing as the steam-engine, we cannot fail to be struck by the extreme obviousness of each advance, and how {33} obstinately it was refused assimilation until the machine almost invented itself.