(7) Another set of factors working towards the production and maintenance of the tendencies to incest are those connected with the dependence of the youthful individual on the family, with all that this implies. We have already, in Chapters IV and V studied the manner in which the inertia of habit, the difficulties involved in the growth of individuality, the efforts required for self-governance, self-maintenance and independence and the tendency to regress to an earlier stage of development in the face of obstacles, all combine to produce the retention of, or the return to, a relatively infantile attitude towards the family. We were there chiefly concerned with the aspects of self-preservation and self-expression rather than with the aspects of love or reproduction, but it is evident that the infantile and childish stages of both aspects must be associated with one another, so that a fixation at an early stage of development with regard to one aspect will be likely to bring with it a corresponding fixation as regards the other. Thus, for instance, an undue reluctance to abandon the conception of the mother as the protector and provider of childhood may easily entail a similar failure of growth on the erotic side. In general it would appear that the inertia of the human mind, which so often involves a failure to emancipate the self from the trammels of the early family life, will tend inevitably to produce a corresponding want of adjustment in the love life. This factor of itself would not suffice to bring about the tendency to incest, but, given the existence of this tendency, it might constitute an influence of very considerable power in maintaining the tendency in question, both in the individual and in the race, and might even be a means of producing a reversion to this tendency in cases where it seemed to have been superseded or outgrown. [Sidenote: The sentiment of parent-love is powerful in virtue of its early formation]