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The infant's love for his mother
EDITOR'S COLUMN
The infant's love for his mother
has little control over his motor apparatus, except for sucking. Moreover, motor maturation is so slow in tile human infant that, by the time some degree of control has been attained, the nature of the motherchild relationship has been obscured by earlier experiences. The two substitute mothers proved equally satisfactory nutritionally. Both groups of infant monkeys drank the same amount of milk and gained weight at the same rate. But they were by no means equally satisfied psychologically, t / o t h groups of infants spent much more time climbing and clinging on the cloth-covered mother than they did on the wire mother, and the time spent in this way increased as they grew older. The infants who secured their food from the wire mother remained with her no longer than feeding required. This observation is in direct contradiction of the view that affection is a response acquired from the association with the satisfaction of hunger or thirst. Harlow's studies emphasize the importance of bodily contact and the immediate comfort which it supplies in forming the infant's attachment for its mother. He points out that in the natural nursing situation intimate bodily contact is effectively guaranteed. The mother who finds nursing a pleasant experience gives her baby plenty
T I J E O R I G I N of the infant's love for his mother has been a subject for much speculation. A widely held view is that the infant learns to love his mother through the association of her face, body, and other physical characteristics with the satisfaction of hunger and thirst, a materialistic interpretation of human behavior. According to psychoanalytic theory the basis is the pleasure of attaining and sucking at the breast. Others hold that the infant's love for his mother is elicited by a variety of experiences which include nursing, physical contact, clinging, and even seeing and hearing. The subject has been put to test by Hatlow 1 in an ingenious series of experiments using newborn monkeys. His studies were designed to compare the importance of nursing and all associated activities with that of bodily contact in eliciting the infant's love for his mother. For this purpose two substitute "mothers" were constructed. One was a bare, welded-wire cylindrical form, surmounted by a crude wooden head a n d face; the other was similiar except that the wire was covered by a sheathing of terry cloth. Four newborn monkeys were assigned to each "mother"; they received their milk from a nursing bottle with its nipple protruding from the mother's "breast." Monkeys are much better suited for this type of study than is the human infant who is so immature at birth that he 643
644
Editor's column
of fondling. Comfort during contact is a decisive factor in the mother-child relationship. Further information on the emotional attachment of the infant monkeys for their substitute mothers was obtained by observing their behavior under various stresses. When the infant monkeys were exposed to a mechanical teddy bear which moved forward beating a drum, they were terrified and rushed headlong for safety. Whether they had been suckled from the wire or the cloth mother they overwhelmingly rushed to the cloth one, clinging to her, and rubbing their bodies against hers. In the early experh~ents the terrified infant might rush to the wire inother, but he soon abandoned her for the cloth one. As experience grew he went directly to the cloth mother more and more. After his fears were assuaged through contact with his mother, he would turn and look at the bear without the least sign of alarm and he might even leave the protection of the mother to explore the object which only a few minutes earlier had reduced him to terror. Similiar results were obtained when the infant monkeys were exposed to other stressful situations, for example, a large room c o n t a i n i n g unfamiliar objects. Here again the infants rushed to the cloth mother, clinging to her, and rubbing against her. The wire mother provided no more reassurance than no mother at all. In a further series of studies an experiment devised by Butler s was adopted. Butler had observed that monkeys enclosed in a dimly lighted box would press a lever to open and reopen a window again and again solely for the purpose of looking out. The rate at which they pressed the lever depended on what they saw through the open window. For example, the sight of another monkey elicited much more interest than a bowl of fruit or an empty room. This curiosity response is innate and already is evident in 3-day-old monkeys. When the 2 groups of infant subjects were tested in a Butler box, the monkeys
October I960
showed as high a response to the cloth mother as to another monkey. On the other hand, they displayed no more interest in the wire mother than in an empty room. Monkeys fed on the wire mother behaved like those fed on the cloth mother. A control group, raised with no mothers at all, found the cloth mother no more attractive than the wire mother and neither were as interesting as another monkey. Harlow has sought to discover types of stimulation other than bodily contact that have to do with the development of infantile affection. One of these is rocking. When the infant monkeys were exposed to two cloth mother substitutes, one stationary, the other rocking, they preferred the rocking one. A rocking crib was preferred to a stationary one. The degree of preference varied from day to day and from monkey to monkey. W a r m t h did not seem to affect the infantmother relationship. Heating the substitute mother did not increase her attractiveness for the infant monkeys. The studies were made in a well-heated laboratory and different results might be obtained in a chillier atmosphere. Harlow presents evidence that clinging itself m a y have some value in promoting psychological and physiologic well-belng. Visual stimuli also enhance the attachment of the infant monkeys. At about 3 months they begin to explore the head, face, and eyes of their substitute mothers, a type of behavior seen somewhat later in human infants. I t is of interest in this connection that, in the process of "imprinting," Lorenz ~ has found that the young of certain species of birds become attached to the first moving object, usually the mother. In a further series of experiments 4 infant monkeys were denied any physical contact with a mother substitute or with other monkeys, thus simulating the situation where human infants are reared without affection. After about 8 months they were placed in cages with access to both cloth and wire mothers. At first they were timid but soon they began to respond much as
Volume 57
Number 4
did the other infants, spending less than an hour a day on the wire mother and 8 to 10 hours on the cloth mother. This was, however, o n l y about half the time spent on the cloth mother by infants raised with her from birth. Obviously, the "orphan" monkeys derived less comfort from the cloth mothers than did the "nonorphan" ones; the early deprivation had altered their capacity to develop a normal affectionate relationship. T o further study the effect of early deprivation, infant monkeys were separated from their cloth mothers at about 5 ~ months of age and then brought together again after about 18 months of separation. The infants showed little or no loss of responsiveness. By contrast, infant monkeys who had been introduced to a substitute
Editor's column
64 5
mother only after the age of 8 months quickly lost whatever responsiveness they had acquired. Clearly the early period of maternal deprivation had altered permanently their capacity for forming a lasting affectionate relationship. Harlow has devised an experimental approach for studying the subtle emotional relationships between mother and infant. His observations have already dissipated much that was speculative and misty. HARRY BAKWIN~ M.D.
REFERENCES
1. Harlow, H. F.: Love in Infant Monkeys, Scient. Am., June, 1959. 2. Butler, R. A.: Curiosity in Monkeys, Scient. Am., February, 1954. 3. Lorenz, K. Z.: King Solomon's Ring, New York, 1952, Thomas Y. Crowell Company.
Comments on tropical pediatric literature: Bepbenium in bookworm therapy T H F. prevention of the various helminthiases, which plays such an important part in the pathology of tropical children, rests ultimately with improving hygiene and sanitation, paralleled by higher standards of general and health education. In the meantime, the search continues for effective anthelminthics which can be used both in the therapy of clinical cases and also in attempts to control, or contain, this type of problem on a community basis by, for example, mass "deworming" of accessible groups of population, such as school children. The hookworm is the intestinal helminth directly responsible for most deaths in childhood in tropical regions, as a result of anemia, due to the severe blood loss which may ensue with heavy worm burdens in poorly nourished and rapidly growing children. Therapy is therefore twofold--the
hemoglobin has to be raised to safe levels and then the parasites removed, as far as possible, by chemotherapy. Standard treatment of hookworm infection in most parts of the world is with tetrachlorethylene (0.1 ml. per kilogram of body weight), given as a single dose in a liquid form on an empty stomach. Experience in the Caribbean has shown that neither starvation nor purgation are needed at any stage? The drug is very cheap, and, in the opinion of most, of low toxicity, although some workers prefer not to use it in grossly anemic children, with hemoglobin levels below 3 Gm. per 100 ml., until an initial transfusion of packed or sedimented red cells has been given cautiously. However, in tropical regions where facilities for blood transfusion do not exist, tetrachlorethylene has been used even in such exsanguinated pa-
The infant's love for his mother
has little control over his motor apparatus, except for sucking. Moreover, motor maturation is so slow in tile human infant that, by the time some degree of control has been attained, the nature of the motherchild relationship has been obscured by earlier experiences. The two substitute mothers proved equally satisfactory nutritionally. Both groups of infant monkeys drank the same amount of milk and gained weight at the same rate. But they were by no means equally satisfied psychologically, t / o t h groups of infants spent much more time climbing and clinging on the cloth-covered mother than they did on the wire mother, and the time spent in this way increased as they grew older. The infants who secured their food from the wire mother remained with her no longer than feeding required. This observation is in direct contradiction of the view that affection is a response acquired from the association with the satisfaction of hunger or thirst. Harlow's studies emphasize the importance of bodily contact and the immediate comfort which it supplies in forming the infant's attachment for its mother. He points out that in the natural nursing situation intimate bodily contact is effectively guaranteed. The mother who finds nursing a pleasant experience gives her baby plenty
T I J E O R I G I N of the infant's love for his mother has been a subject for much speculation. A widely held view is that the infant learns to love his mother through the association of her face, body, and other physical characteristics with the satisfaction of hunger and thirst, a materialistic interpretation of human behavior. According to psychoanalytic theory the basis is the pleasure of attaining and sucking at the breast. Others hold that the infant's love for his mother is elicited by a variety of experiences which include nursing, physical contact, clinging, and even seeing and hearing. The subject has been put to test by Hatlow 1 in an ingenious series of experiments using newborn monkeys. His studies were designed to compare the importance of nursing and all associated activities with that of bodily contact in eliciting the infant's love for his mother. For this purpose two substitute "mothers" were constructed. One was a bare, welded-wire cylindrical form, surmounted by a crude wooden head a n d face; the other was similiar except that the wire was covered by a sheathing of terry cloth. Four newborn monkeys were assigned to each "mother"; they received their milk from a nursing bottle with its nipple protruding from the mother's "breast." Monkeys are much better suited for this type of study than is the human infant who is so immature at birth that he 643
644
Editor's column
of fondling. Comfort during contact is a decisive factor in the mother-child relationship. Further information on the emotional attachment of the infant monkeys for their substitute mothers was obtained by observing their behavior under various stresses. When the infant monkeys were exposed to a mechanical teddy bear which moved forward beating a drum, they were terrified and rushed headlong for safety. Whether they had been suckled from the wire or the cloth mother they overwhelmingly rushed to the cloth one, clinging to her, and rubbing their bodies against hers. In the early experh~ents the terrified infant might rush to the wire inother, but he soon abandoned her for the cloth one. As experience grew he went directly to the cloth mother more and more. After his fears were assuaged through contact with his mother, he would turn and look at the bear without the least sign of alarm and he might even leave the protection of the mother to explore the object which only a few minutes earlier had reduced him to terror. Similiar results were obtained when the infant monkeys were exposed to other stressful situations, for example, a large room c o n t a i n i n g unfamiliar objects. Here again the infants rushed to the cloth mother, clinging to her, and rubbing against her. The wire mother provided no more reassurance than no mother at all. In a further series of studies an experiment devised by Butler s was adopted. Butler had observed that monkeys enclosed in a dimly lighted box would press a lever to open and reopen a window again and again solely for the purpose of looking out. The rate at which they pressed the lever depended on what they saw through the open window. For example, the sight of another monkey elicited much more interest than a bowl of fruit or an empty room. This curiosity response is innate and already is evident in 3-day-old monkeys. When the 2 groups of infant subjects were tested in a Butler box, the monkeys
October I960
showed as high a response to the cloth mother as to another monkey. On the other hand, they displayed no more interest in the wire mother than in an empty room. Monkeys fed on the wire mother behaved like those fed on the cloth mother. A control group, raised with no mothers at all, found the cloth mother no more attractive than the wire mother and neither were as interesting as another monkey. Harlow has sought to discover types of stimulation other than bodily contact that have to do with the development of infantile affection. One of these is rocking. When the infant monkeys were exposed to two cloth mother substitutes, one stationary, the other rocking, they preferred the rocking one. A rocking crib was preferred to a stationary one. The degree of preference varied from day to day and from monkey to monkey. W a r m t h did not seem to affect the infantmother relationship. Heating the substitute mother did not increase her attractiveness for the infant monkeys. The studies were made in a well-heated laboratory and different results might be obtained in a chillier atmosphere. Harlow presents evidence that clinging itself m a y have some value in promoting psychological and physiologic well-belng. Visual stimuli also enhance the attachment of the infant monkeys. At about 3 months they begin to explore the head, face, and eyes of their substitute mothers, a type of behavior seen somewhat later in human infants. I t is of interest in this connection that, in the process of "imprinting," Lorenz ~ has found that the young of certain species of birds become attached to the first moving object, usually the mother. In a further series of experiments 4 infant monkeys were denied any physical contact with a mother substitute or with other monkeys, thus simulating the situation where human infants are reared without affection. After about 8 months they were placed in cages with access to both cloth and wire mothers. At first they were timid but soon they began to respond much as
Volume 57
Number 4
did the other infants, spending less than an hour a day on the wire mother and 8 to 10 hours on the cloth mother. This was, however, o n l y about half the time spent on the cloth mother by infants raised with her from birth. Obviously, the "orphan" monkeys derived less comfort from the cloth mothers than did the "nonorphan" ones; the early deprivation had altered their capacity to develop a normal affectionate relationship. T o further study the effect of early deprivation, infant monkeys were separated from their cloth mothers at about 5 ~ months of age and then brought together again after about 18 months of separation. The infants showed little or no loss of responsiveness. By contrast, infant monkeys who had been introduced to a substitute
Editor's column
64 5
mother only after the age of 8 months quickly lost whatever responsiveness they had acquired. Clearly the early period of maternal deprivation had altered permanently their capacity for forming a lasting affectionate relationship. Harlow has devised an experimental approach for studying the subtle emotional relationships between mother and infant. His observations have already dissipated much that was speculative and misty. HARRY BAKWIN~ M.D.
REFERENCES
1. Harlow, H. F.: Love in Infant Monkeys, Scient. Am., June, 1959. 2. Butler, R. A.: Curiosity in Monkeys, Scient. Am., February, 1954. 3. Lorenz, K. Z.: King Solomon's Ring, New York, 1952, Thomas Y. Crowell Company.
Comments on tropical pediatric literature: Bepbenium in bookworm therapy T H F. prevention of the various helminthiases, which plays such an important part in the pathology of tropical children, rests ultimately with improving hygiene and sanitation, paralleled by higher standards of general and health education. In the meantime, the search continues for effective anthelminthics which can be used both in the therapy of clinical cases and also in attempts to control, or contain, this type of problem on a community basis by, for example, mass "deworming" of accessible groups of population, such as school children. The hookworm is the intestinal helminth directly responsible for most deaths in childhood in tropical regions, as a result of anemia, due to the severe blood loss which may ensue with heavy worm burdens in poorly nourished and rapidly growing children. Therapy is therefore twofold--the
hemoglobin has to be raised to safe levels and then the parasites removed, as far as possible, by chemotherapy. Standard treatment of hookworm infection in most parts of the world is with tetrachlorethylene (0.1 ml. per kilogram of body weight), given as a single dose in a liquid form on an empty stomach. Experience in the Caribbean has shown that neither starvation nor purgation are needed at any stage? The drug is very cheap, and, in the opinion of most, of low toxicity, although some workers prefer not to use it in grossly anemic children, with hemoglobin levels below 3 Gm. per 100 ml., until an initial transfusion of packed or sedimented red cells has been given cautiously. However, in tropical regions where facilities for blood transfusion do not exist, tetrachlorethylene has been used even in such exsanguinated pa-