of the response systems mediating escape and those mediating attachment has already been emphasized. Inevitably anything which frightens the primate infant serves to intensify his attachment behaviour and, in the absence of his mother, to magnify his anxiety. Yerkes, generalizing about infant chimps brought up with their mothers in captivity, describes how ‘even at 2 years of age, after it can feed itself and move about independently, the youngster will rush to its mother or to other adults in any emergency.’
Human mothers are familiar with such patterns of behaviour. Just as the child in his second or third year seems to be becoming more independent, he has a phase when he becomes more demanding again. Sickness, fright, or a period of separation often account for it. So too does the mother’s own mood. As often as not when a young child becomes fretful and anxious it is because his mother has been upset, either with him or with someone or something else, and has consequently been brusque and irritable with him. She is less patient, her tone of voice changes, her expression is different: these are the things to which young children are keenly sensitive. Furthermore, it is not uncommon for mothers to use the fear of separation – or withdrawal of love which is substantially the same thing – as a sanction to enforce good behaviour. Sometimes this is done as a deliberate policy, more often almost unconsciously. No matter how expressed, however, it is a powerful sanction and, as Fairbairn and many others have emphasized, inevitably increases the child’s proneness to separation anxiety. It is this aspect of the theme that Sullivan picked on almost exclusively, thereby making his views in the weight he gives to parental influence in the genesis of neurotic anxiety the counterpart of Klein’s in the weight she attributes to constitutional factors. This debate is referred to again in the next section where we consider why one child rather than another becomes prone to excessive separation anxiety.
Nevertheless, even though experiential factors of one kind or another can frequently be seen to account for short‐term variations in intensity of attachment behaviour, on some occasions it is very difficult to trace the reasons. Perhaps in human children it is the same as it was with Gua, whose ‘attachment would wax and wane in a slow irregular rhythm’ during the nine months she was with the Kelloggs. Systematic records are obviously required.
As regards the long‐term changes, both in chimps and humans the instinctual response systems mediating attachment and escape behaviour slowly modify. Not only do they become less readily activated and, when activated, active at a lower level of intensity, but they come to be organized around an increasing range of objects. These two kinds of change appear to be taking place during the same period of the life span and consequently are not always easy to differentiate.
The processes underlying the long‐term reduction in the frequency and intensity of their activation, with its concomitant reduction in separation anxiety, are unknown. As we have seen, their ready activation in early childhood is easily accounted for by their survival value. Since as the child grows older they become less necessary, it may well be that there is operative a maturational process designed to restrict their activity, as sexual activity is restricted at the menopause. Nevertheless experience and learning certainly play a considerable part also. As time goes on, the better grounds a child has to believe that his parents love him and will return to him, the less apprehensive will he be both before their departure and whilst they are away; the weaker the grounds, the more anxious on these occasions.
Although I believe such views to be theoretically plausible and, so far as there are relevant data, empirically well based, it must be recognized that they are not those which have been advanced by leading psycho‐analysts, many of whom have thought that the growth of independence is impossible without the frustration of earlier needs. Freud held that it is possible to give a child too much affection and that it is this which prolongs the phase of dependence and promotes increased separation anxiety; a critique of this view is postponed to the next section. Melanie Klein shares the same outlook but invokes a different mechanism. In questioning how the child ever detaches himself from his mother, she suggests that ‘the very nature of this overstrong attachment … tends to drive him away from her because (frustrated greed and hatred being inevitable) it gives rise to the fear of losing this all‐important person, and consequently to the fear of dependence upon her’ (Klein & Riviere, 1937). Although a process of this kind is well known as one which underlies a premature development of independence,19 I believe it to be the result of avoidable frustration and to lead to independence of a special and often pathological kind. I know of no reason to suppose it is responsible for its healthy growth.
As regards the second component of the long‐term changes, the increasing range of objects toward whom attachment behaviour is directed, probably this is also a result both of maturational change and of learning. Thus the very capacity to include, even at a lower level of preference, a number of different people is something which may well become increased between, say, 18 months and 3 years by maturational processes. Even so, precisely who is included is obviously learned, and the number who become trusted by any particular child, whilst always limited, is evidently in large part the result of experience.
Once again it is instructive to hear of comparable changes in chimpanzees. Reading Yerkes’s account, one gains the impression that, in chimps, initially the shift may be entirely one of object and that intensity of response remains unchanged. Generalizing again from his observations of chimps in captivity, he writes of the developing infant: ‘Gradually a striking change in behaviour becomes evident. The initial specific clinging dependence upon the mother gives place rapidly to a generalized dependence on the extending social environment. … Need for social stimulation, such as is provided by companions, becomes so strong during late infancy and early childhood that isolation causes varied symptoms of deprivation.’ As the chimpanzee child grows older, however, the intensity of the attachment responses themselves seems to diminish: ‘Maternal dependence normally is outgrown during infancy, and similarly, extreme social dependence tends to be outgrown during childhood and adolescence.’
Primary anxiety arising from separation either from mother‐figure or companions is thus a function of age. The period when the individual is especially vulnerable is whilst the response systems mediating attachment and escape are not only easily activated at high intensity but are narrowly directed towards one, or at most a few, figures. Once there is a diminution in the readiness with which the response systems are activated, or the growing child, chimp or human, becomes able to accept temporary substitutes more readily, vulnerability decreases. So far as my own observations go, I have the impression that in humans these changes do not often take much effect until the child has reached about 2 years 9 months, though the age varies considerably from child to child.
Origin of Separation Anxiety of Pathological Degree
Earlier in the paper I have made it clear that, on the hypothesis advanced, primary anxiety will occur whenever any (or at least one of a number of) instinctual response systems is activated and not terminated. The primary anxiety arising when a young child is separated from his mother is thus only a special case of a more general phenomenon. Nevertheless, clinical experience suggests that it is of peculiar pathogenic significance and, if this is so, the problem remains why it should be so. The following explanation appears plausible. In the first place, the phase during which the human infant’s capacity for locomotion is limited is a long one. As a result, whether or not his attachment responses are terminated turns for some years on the initiative of others, especially his mother: he is entirely dependent on their goodwill. In the second, there is the close linkage between the instinctual response systems mediating attachment behaviour and those mediating escape, so that, whenever a young child is separated from his mother and such substitutes as he will accept, there is the risk of his experiencing not only primary anxiety but also fright, and both in conditions where there is no one available to provide comfort and security. This makes the situation doubly alarming to him and accounts for the intensity of distress we observe. Finally, because of their tremendous importance for survival, both these classes
