The term “crisis” is not to be understood in a violent sense. It is involved in any disturbance of habit. There is a crisis in the boy’s life when he leaves home. The emancipation of the Negro and the immigration of the European peasant are group crises. Any strain of crisis involves three possible changes: greater fitness, reduced efficiency, or death. In biological terms, “survival” means successful adjustment to crisis, accompanied typically by a modification of structure. In man it means mental stimulation and greater intelligence, or mental depression, in case of failure.[12] Under the conditions imposed by city life in which individuals and groups of individuals, widely removed in sympathy and understanding, live together under conditions of interdependence, if not of intimacy, the conditions of social control are greatly altered and the difficulties increased. The problem thus created is usually characterized as one of “assimilation.” It is assumed that the reason for rapid increase of crime in our large cities is due to the fact that the foreign element in our population has not succeeded in assimilating American culture and does not conform to the American mores. This would be interesting, if true, but the facts seem to suggest that perhaps the truth must be sought in the opposite direction. One of the most important facts established by the investigation concerns the American-born children of immigrants—the “second generation.” The records of convictions in the New York Court of General Sessions during the period from October 1, 1908, to June 30, 1909, and of all commitments to Massachusetts penal institutions, except those to the state farm, during the year ending September 30, 1909, form the basis of this analysis of the criminal tendencies of the second generation. From these records it appears that a clear tendency exists on the part of the second generation to differ from the first or immigrant generation in the character of its criminality. It also appears that this difference is much more frequently in the direction of the criminality of the American-born of non-immigrant parentage than it is in the opposite direction. This means that the movement of the second-generation crime is away from the crimes peculiar to immigrants and toward those of the American of native parentage. Sometimes this movement has carried second-generation criminality even beyond that of the native-born of native parentage. Of the second-generation groups submitted to this comparison, one maintains a constant adherence to the general rule above referred to, while all the others at some point fail to follow it. This unique group is the Irish second generation.[13]