Bad habits and pernicious results: thumb sucking and the discipline of late-nineteenth-century paediatrics.

In the late nineteenth century a new subject-the infant behaviour of thumb suckingappeared on the medical stage. Thumb sucking emerged in the literature of the diseases of children in the late 1870s and had by 1910 become a standard entry in paediatric textbooks, where it remained for the next forty years. The habit is barely mentioned in medical textbooks today, but for turn-of-the-century paediatricians it was an example of childhood pathology. It was a serious matter. The topic has not previously received attention in the history of medicine and the only references to it appear to be scattered in commentaries on the history of child rearing.5 But, as an infant behaviour, it was evidently not a new phenomenon and in the late nineteenth century was often regarded as a source of comfort and pleasure for child and parent. When it began to be considered in medical discourse, however, it was redefined as pathology: a pathology of ugly dental malformation and worrying sexual behaviour.