The principles of sleep training are sociocultural (not scientific) and became dominant long before evidence-based practice was a thing!

You could say that sleep training is very 'last century'!

Sleep training is an outdated health system response to the very chaotic feeding and sleep experiences endured by many women after the birth of their babies, dating from the 1950s. This miserable chaos, of screaming babies who failed to sleep or gain weight, and breastfeeding that didn't seem to work, was often (though of course not always) accidentally created by medical and nursing practices within hospital settings. Back in the 1950s and 1960s, these practices made it very difficult for many mothers and their babies to get in sync, and were accompanied by high rates of formula use.

Routinised feeds and sleep became popular in maternity hospital wards after the Second World War as the first wave of a school of psychology called behaviourism swept the world. This first wave of behaviourism fitted in nicely enough with the Scientific Motherhood approaches of the early 20th century, promoted for example by New Zealand paediatrician Dr Frederick Truby King.

Sleep training principles pre-date contemporary developmental neuroscience

Sleep training principles pre-date contemporary developmental neuroscience - which is why many sleep coaches and programs, keen to integrate the principles of responsive parenting, have modified the sleep training principles and call their programs 'responsive or gentle settling' (without realising they are still using key sleep training principles, which can worsen sleep and increase family distress and stress).

In 1974, when it was still compulsory for 14-year-old schoolgirls in my home state of Queensland, Australia, to complete a subject called Mothercraft, I was taught that

• “Good sleeping habits should begin in the earliest months of life, for habits learnt in babyhood are likely to last into childhood.

• “So much sleep is needed because his body is growing quickly and his brain is developing very fast and his nervous system develops best when he is asleep. If he does not have sufficient sleep and rest, he will not grow so well, he will be nervous and fretful, and when overtired will not eat his meals well.

• “Some form of routine is good for the baby because …. good habits are formed which will last him all his life. His nervous system develops best in calm, unchanging surroundings …

• “Do not play or talk to the baby … when he is supposed to be going to sleep. Do not awaken the baby to show him to visitors.”

These are extracts from the handouts I was given as a schoolgirl by the Queensland Maternal and Child Welfare Service. You can see that health authorities in the 1970s had high levels of concern about the brain effects of overstimulation of the nervous system and overtiredness, beliefs which persist in our health systems today. Authorities believed these negative effects on the nervous system could be prevented by strict sleep and feeding routines, good habits, and by not overstimulating or overfeeding babies. This is how sleep training was promoted as 'scientific' well before the rise of evidence-based medicine.

In fact, sleep training is a socioculturally-created infant care practice or belief system, which started well before we began to use research studies to guide practice. You can find out more about this here.