The self preservation instinct appears to our consciousness under the guise of that deep rooted clinging to life, that desire to live, which characterises every living thing. It is this instinct, functioning simply in simply organised creatures, that leads them to seek food and avoid danger, and also causes that complex organism, a civilised man, to carry out the elaborate activities of “earning a living.”
It is essentially a selfish instinct, for it leads the individual to regard his own welfare alone, and to consider others only so far as their existence is essential to his. For instance, shooting and hunting during the breeding season are forbidden by law, not out of consideration for the hunted creatures, but because the continuation of their species is useful to us.
Its influence, however, is often modified by the two other great instincts whose influence may become so strong under certain circumstances as to induce a man not only to disregard his own interests, but even to lay down his life for others.
In many varieties of animals, however, only two instincts are present, self-preservation and reproduction; but in animals that are associated together into herds or packs, a third instinct is developed, the social instinct. When this occurs, the functioning of the self-preservation instinct is greatly modified; the individual no longer owes his existence solely to his power to cope with his environment, but depends mainly upon his ability to keep his place in the herd; and upon the social organisation devolves the task of adaptation and survival. The strayed sheep is soon hunted down, the solitary wolf starves.
This is equally true of man, who is also a social animal. The misery of Central Europe, in the breakdown of social organisation following upon the war, has shown us the helplessness of the individual human being and his complete dependence upon herd life.
The self-preservation instinct and its ruthless functioning under the law of natural selection has furnished a theme to many moralists and sociologists of the materialistic type, but they are apt to forget that the socialisation of humanity has changed the nature of the problem; the unit of survival is no longer the individual, but the social organisation of which he is a member. The law of self-preservation has given place to the law of group preservation, and the centre of psychic gravity is shifted. The importance of this point cannot be over-estimated in practical psychology.
By some psychologists the instinct of nutrition is distinguished from that of self-preservation, but for all practical purposes they are identical.
It must be borne in mind, in applying the standards of psychology to the human character, that in the more highly developed types of human being the self-preservation instinct is not fulfilled simply by the continuance of physical life; there is self-preservation of the personality as well as of the bodily existence, and unless a man has adequate scope for self-expression and self-development, he will experience that sense of incompleteness and imperfection characteristic of the repression of an instinct.