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9 Specific Consequences of the Evolution of Primate Mentality

This somewhat lengthy digression will have made it clear that the evolution of the mind of individual memory and the consequent submergence of the mind of hereditary memory is a process discernible in the highest primate, man, as well as in that comparatively lower primate, the chacma. The vast and fundamental difference which exists between the old mind and the new in its method of reaction to the environment has had, as may be imagined, certain farreaching consequences; and the chacma, whose behaviour is directed chiefly by the new mentality, seems to exhibit these consequences in no uncertain manner. Some consideration of these effects is necessary.

The evolution of instinctive mentality is always in the direction of more com-

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plete specialisation. The higher and more complex an hereditary instinct is, the more efficiently does it react under certain definite natural conditions - namely, the conditions that selected it - and the less able it is to direct behaviour beneficially under changed conditions or new ones. Whenever an animal adapts itself suddenly to changed conditions, it will be found that this is not a reaction of the phyietic memory, but is invariably due to its inhibition, partial or complete, by the acquisition of individual causal memory. The animal adapts itself not by means of the instinct but in spite of it.

Heredity of behaviour is one of the distinguishing marks of the phyletic mind. An instinct is sometimes so complex and its beneficial reaction dependent upon such a long chain of causes and effects that the essential difference between ‘instinct’ and ‘intelligence’ is easily missed. Many careful and distinguished observers have regarded these complex instincts as a complete vindication of the contention that such behaviour is directed by ‘intelligence’. If the memory which directs behaviour is hereditary, it is quite certainly instinctive. An individually acquired environmental causal memory is never transmitted from parents to offspring. And because an instinct is in itself unchangeable, except through the long and dangerously destructive process of natural selection, its possession always entails a disadvantageous limitation of the existence-scope of the organism whose behaviour it controls. It is here that the evolution of the new mind becomes apparent, working towards the breaking down of disadvantageous limitation. It is the great psychic generalising process of natural selection.

By the acquisition of individual memories an organism is to a proportionate extent freed from the stringent necessity of limiting its activities to a defined environment. But even with this new weapon in its armoury the struggle of a species against nature is still hampered by the existence of hereditary behaviour. Its tendency is always to neutralise the beneficial action of individual memory. Selection therefore gradually renders inoperative the mind which determines hereditary behaviour. As one ascends in the evolutionary scale through the primates, the mind of hereditary memory becomes more and more inactive. Most of its attributes, although still in existence as the functions of existing brain centres, are inhibited by the new mentality from taking any share in the direction of behaviour. Some of these instinctive attributes which are still beneficial, and therefore necessary, seem to be controlled by the new mind. Their reaction can in different degrees be either inhibited or called into action voluntarily. This is so, as will be seen, in the higher primates even in the case of so universal and essential an instinct as the sexual sense. Under such conditions an instinct, even when operative, loses its stereotyped character, that fixed and changeless response to outward stimulation which is the outstanding characteristic of activity in the purely instinctive soul.

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The power which causal memory confers of immediate adaptation to changed environmental conditions affords a species an enhanced protection against the hostility of nature generally, and this has a remarkable result. The elements in nature hostile to organic life - and that seems to be all nature - constitute the means by which natural selection operates. Natural selection is in effect the elimination of the not sufficiently specialised. When, therefore, an organism is protected against this active hostility, it is to the same extent protected against natural selection. It is something in the nature of a vicious circle: natural selection in the end destroying itself.

It will be seen presently that this protection can hardly be regarded, from the point of view of well-being of the species, as a beneficial process. Our present knowledge of nature precludes the concept of any other force which could make for the endurance of organic beings, and we are, therefore, apparently face to face with the inevitable conclusion that a condition disadvantageous to a species has been attained by natural selection. At first glance it seems a contradiction in terms. The very fundamental conception of selection is the retention of beneficial attributes only. A disadvantageous condition cannot be brought about by natural selection.

This apparent paradox is not a real one. It is based on a confusion of ideas, and practical experience of nature soon teaches one to distinguish between a primary benefit and a secondary accidental disadvantage resulting from it. As long as the accidental disadvantage does not completely outweigh the main advantage, it will continue as a satellite attendant upon its primary. Such an accidental disadvantageous result is the protection from natural selection in the chacma. The primary advantage clearly was the removal of environmental limitation, and this removal was brought about by a process destructive of natural selection itself.

The difficulty of understanding such a simple and universal law is increased when the mind is influenced by that trend of abstract speculation which is apt to regard evolution by means of natural selection as some infallible process tending towards some ideal state of perfection. A direct and practical knowledge of nature soon corrects this wrong idea and renders comprehensible how such an apparently disadvantageous condition as protection from selection could have been brought about in a species. It becomes at once evident that in the whole scheme of organic evolution no ‘perfection’ has ever been attained and that in the nature of things it is unattainable. The end of natural selection is specialisation, and every specialisation is at once followed by a number of disadvantages which may increase in valency in proportion to the progress of the specialisation until they neutralise entirely the benefit which it originally conferred. The specialisation then becomes selectively modified and this modification means only specialisation in a new direction. The process, therefore, is

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an unending one, and the attainment of perfection - that is, an organism in perfect accord with its environment - is a practical impossibility. Natural selection regularly brings about accidental and often disadvantageous consequences, and the reduction of the power of natural selection by the acquisition of non-hereditary environmental memories is an example.

This enlargement from the confining tendencies of the instinctive mind was the immediate benefit conferred upon the chacma by the attainment of a dominant individual causal memory. We have seen how it has enabled the species to penetrate the most varied natural environments. They have indeed become citizens of a large world. For them restriction to a locality no longer exists. For them there is no longer a supreme danger in the invasion of threatening competition or any sudden or radical change in natural conditions. A door of escape is always open to them. They can either adapt themselves instantly to the new conditions or migrate, even where such migration entails a new environment.

The psychic power of immediate adaptation, by the acquisition of and reaction to individual causal memories, culminates in man, the highest primate. His exalted development of the new mentality has rendered the species heir to all the earth and the fullness thereof. Against his invasion neither the sub-tropical deserts nor the polar ice has been proof. But if this was the benefit which causal memory conferred upon the chacma, then the indirect accidental result of that evolutionary process - namely, the protection against stringent natural selection - has had results in other directions which, one is inclined to believe, must eventually have a profound effect upon the fate of any species.

Whenever a species is protected from the severity of natural selection, certain definite results ensue, and these are always proportionate to the extent and duration of the protection. These changes are included under the general and somewhat unmeaningful term ‘degeneration’, and they are, of course, especially noticeable in man and in domestic animals, where natural selection is at its lowest ebb.

When these changes are compared, it is found that two of them seem to assume prime importance. These are (1) divergence from specific type, and (2) disturbances of the sexual sense.

On examination, it appears that the real cause of their apparent importance is due two factors: They represent the sum of a great number of changes which affect every organ and the function of every organ; and the fate of the species seems to be so deeply involved in them. It is to these two changes, as they relate to the chacma, that the next two chapters will be devoted.