This essay is an historical reflection on the increasing measurability of the human body and behaviour. Using the history of the baby book, I will illustrate the way in which taking measurements can become a ritual. The pages of the baby book for documenting weight and height measurements had their origins in the medical domain. It was important for the doctor that mothers would take responsibility for their children’s health and be given the tools to do this, but for parents these measurements started to symbolize the fact that the baby was developing into a child with its own personality. Because of this, taking measurements and recording them acquired a ritualistic aspect. This suggests that today’s self-tracking with digital devices as well can be regarded as a rite of modern life, in which the numbers themselves may at times have less meaning than the repeated action of measurement.
Conflict of interest and financial support: Dr Sysling reports receiving grants from NWO (Netherlands Organisation for Scientific Research) during the conduct of the study. An ICMJE form provided by the author is available online along with the full text of this article.