But the critics say that it is not the lack of general or logical training of the individual person which obstructs the path of justice. The trouble lies rather in the mutual influence of the twelve men. The more persons work together, the less, they say, every single man can reach his highest level. They become a mass, with mass consciousness, a kind of crowd in which each one becomes oversuggestible. Each one thinks less reliably, less intelligently, and less impartially than he would by himself alone. We know how men in a crowd do indeed lose some of the best features of their individuality. A crowd may be thrown into a panic, may rush into any foolish, violent action, may lynch and plunder, or a crowd may be stirred to a pitch of enthusiasm, may be roused to heroic deeds or to wonderful generosity; but whether the outcome be wretched or splendid, in any case it is the product of persons who have been entirely changed. In the midst of the panic or in the midst of the heroic enthusiasm, no one has kept his own characteristic mental features. The individual no longer judges for himself; he is carried away, his own heart reverberates, with the feelings of the whole crowd. The mass consciousness is not an adding-up, a mere summation, of the individual minds, but the creation of something entirely new. Such a crowd may be pushed into any roads; chance leaders may use or misuse its increased suggestibility for any ends. No one can foresee whether this heaping up of men will bring good or bad results. Certainly the individual level of the crowd will always be below the level of its best members. And is not a jury necessarily such a group with a mass consciousness of its own? Every individual member is melted into the total, has lost his independent power of judging, and has become influenced through his heightened suggestibility and social feeling by any chance pressure which may push toward error as often as toward truth.
But if such arguments are brought into play, it is evident that it is no longer a legal question, but a psychological one. The psychologist alone deals scientifically with the problem of mutual mental influence and with the reënforcing or awakening of mental energies by social coöperation. He should accordingly investigate the question with his own methods, and deal with it from the point of view of the scientist. This means he is not simply to form an opinion from general value impressions and to talk about it as about a question of politics, where any man may have his personal idea or fancy, but to discover the facts by definite experiments. The modern student of mental life is accustomed to the methods of the laboratory. He wants to see exact figures, by which the essential facts come into sharp relief. But let us understand clearly what such an experiment means. When the psychologist goes to work in his laboratory, his aim is to study those thoughts and emotions and feelings and deeds which move our social world. But his aim is not simply to imitate or to repeat the social scenes of the community. He must simplify them and bring them down to the most elementary situations, in which only the characteristic mental actions are left.