CRYING BABY ≠ PAIN

For much of history, there was a mixed opinion on infant pain. It wasn’t until the 20th century that scientists started to question and experiment on the idea. This was labeled “Infant Pain Denial.” The experiments conducted to research this hypothesis included pinpricks and electric shocks (Rodkey and Riddell). However, one of the most influential figures in this discussion was Myrtle McGraw, a researcher who studied infant neurological and motor development at Columbia University. Among her experiments, the 1941 “pinprick experiment” played a significant role in shaping medical assumptions about infant pain, despite leading to deeply flawed conclusions.

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In this study, McGraw tested seventy-five infants ranging from newborns to four years old. The researchers applied pinpricks to different parts of the infants’ bodies to observe their reactions to physical stimuli. Because infants could not verbally describe their experiences, the researchers relied on visible responses such as crying, limb withdrawal, and movement. However, McGraw placed particular emphasis on the limited and inconsistent responses of newborns. She interpreted this lack of reactions as evidence that very young infants had reduced pain sensitivity, rather than recognizing that their nervous systems and motor control were still developing and might limit how they expressed distress.

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This misinterpretation had an influential consequence. The idea that infants did not fully feel pain became widely accepted in medical practice for decades. As a result, many newborns underwent surgeries with little or no anesthesia from the 1940s and well into the 1980s. Instead of pain relief, physicians often administered paralytic drugs such as curare, which immobilized infants without addressing pain. Because the infants could not move or cry, it reinforced the false belief that they were not suffering.

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The assumptions influenced by studies like McGraw’s persisted for nearly forty years. It was not until the 1980s that this belief began to be seriously challenged. New research in neonatal physiology demonstrated that infants not only feel pain but may experience it more intensely due to their developing nervous systems. It was only in 1984-1986 that American parents discovered the longstanding practice of surgeons to operate on infants without the use of painkillers (Birth, June 1986, Letters, 124-125).

The ethical issues around the original experiment are important to consider. Informed consent standards in the 1940s were much less developed than today, and there is little evidence that parents were fully informed about the nature or risks of such procedures. This reflects a broader trend in early medical research, where vulnerable populations, including infants, were often involved in experiments without meaningful consent or oversight. Ultimately, the pinprick experiment shows how flawed interpretations of data can have long-lasting and harmful effects. Although McGraw wanted to study neurological development, her conclusions led to decades of unnecessary suffering for infants in medical settings. The main point is not just that scientific understanding changes, but that caution, ethical responsibility, and careful evaluation of evidence are crucial, especially when research directly affects patient care.

Sources:

Rodkey, Elissa  N., and Rebecca  Pillai Riddell. “The Infancy of Infant Pain Research: The Experimental Origins of Infant Pain Denial - The Journal of Pain.” Sciencedirect, www.sciencedirect.com/science/article/pii/S1526590013000254. Accessed 13 Mar. 2026. 

Geoffrey T. Falk, Ulf Dunkel. “Babies Remember Pain.” CIRP.Org, 1989, www.cirp.org/library/psych/chamberlain/. Accessed 13 Mar. 2026.

Neural Maturation as Exemplified in the Changing Reactions of the Infant to Pin Prick by Myrtle B. McGraw (https://www.jstor.org/stable/1125489?origin=crossref)