THE CONDITION, known as anaphylaxis, is well-known in connection with hay-fever, asthma, and influenza. There is a strictly comparable phenomenon in the case of different articles of diet; shell fish and almonds at times produce the most intense urticarial rashes, and some babies, and for the matter of that some grown-up individuals, display such marked intolerance of cows’ milk, that as an article of diet it must be permanently abandoned. The exact significance of anaphylaxis in pathology and dietetics and the best methods of dealing with it are not yet clearly understood.

The phenomenon of anaphylaxis in its relationship to food idiosyncrasies in the infant must clearly be distinguished from another form of intolerance to special articles of diet, which has a purely psychological basis.

The lower nerve centres of the brain and their subconscious activities play a very important part in the behaviour of the infant. Young infants behave purely as automatons; in response to suggestion they act exactly like deeply hypnotized persons or well trained animals. But only simple and habitual reflexes can at first be elicited, although compound reflexes are soon acquired, and then can be very easily provoked by suggestion.

In older individuals, in whom the powers of reason have become developed, the direct influence of suggestion may be counteracted by innumerable inhibitions, but in babies, animals and hypnotized individuals the call of suggestion is imperative, and the exact form the response takes is determined by the nature of the previous responses, in other words by habit.

Thus, to take a simple example, the sucking reflex is one of the earliest and most easily elicited of all the inborn mechanisms of an infant, the imperativeness of this habit is well illustrated in the tyrannical and pernicious influence of the “comforter”. The presence of a teat between the lips acts as the suggestion to suck, and the younger the infant the more imperative the call, but as the infant grows older inhibitions and conflicting reflexes interfere with the purity and spontaneousness of the response.

We find, for instance, that, in giving “test feeds” to infants at our Infant Consultations at the St Marylebone General Dispensary, quite young infants take the breast better than older infants, who are more easily distracted by the strangeness of the environment.

A baby treated for spastic diplegia by galvanism

As an instance, among the many I could give, of the influence of suggestion in quite a young infant, I refer to the case of a baby, two months old.

This baby had a very severe spastic diplegia from which it subsequently died. My opinion was asked as to whether any further steps could be taken to restrain the severe spasm into which the muscles passed, the moment they were brought into action.

The condition had been treated with some success by galvanism, that is to say, in so far that the spasm relaxed by the application of the positive electrode to the affected muscles.

The interesting feature, which illustrates the point I wish to make clear, is that relaxation of the spasm resulted equally well whether the electric current was turned on or not; in other words, the laying on of the electrode acted by suggestion and not by reason of the direct action of galvanism.

A baby who vomited when fed desiccated milk

I now give one instance of the manner in which suggestion acts in determining the so-called food idiosyncrasies:

A fat flabby baby, fed on condensed milk, was brought to my Infant Consultations for treatment and advice. Among other details, I recommended that the infant should be gradually weaned from the condensed milk, and placed on a diet of desiccated milk.

Unfortunately, the mother gave too large a quantity of the dried milk on the first occasion, thus omitting to give the infant time to accommodate to the changed digestive requirements, with the consequence that the infant was violently sick. Hereafter the baby was sick every time it was supplied with the desiccated milk, no matter how little was given.

I came to the conclusion that this was due to suggestion and not to anaphylaxis. And to test my theory I instructed the mother to try the effect of adding the dried milk in such a way that the infant could not follow the operation with its eyes or ears, for I believed that the sight or the sound of the milk powder being taken out of the tin might be the effective stimulus.

On the occasion of her next visit the mother reported to me the success of the experiment, and told me that when the food was mixed in an adjoining room, the infant could take equal quantities of dried milk and condensed milk without vomiting.

As a control experiment, I now instructed her to go through the process of opening the tin and of pretending to add some of its contents to the condensed milk, but to be careful not to allow any of the milk powder to reach the bottle. The success of the experiment was again striking in proving the psychological basis of the idiosyncrasy, for now the infant vomited just as persistently as he did when the powder was really added.

This case illustrates very forcibly how important the psychological factor is in the management of infants, and how carefully the motives of an infant’s behaviour should be investigated by the analytical method.