Sleep begets sleep...or does it?

Is the phrase “sleep begets sleep” true?

Short answer:

No.

Long answer:

A human, regardless of whether they are a baby or not, can only manage a certain amount of sleep in 24 hours. How much sleep one human needs revolves around their individual sleep needs and what they are doing from day to day, babies are no different.

The idea that sleep begets sleep is not founded in any evidence and doesn’t align with what is happening biologically with sleep. Parents who swear that their baby getting more sleep helped with sleep will often have a baby that has higher sleep needs and becomes dysregulated if their sleep needs aren’t being met. Therefore, the baby is happy if they get the sleep they need, and if they aren’t getting that sleep, they become dysregulated & cortisol rises which means it is hard to get them to sleep. Sleep begets sleep is not what is happening in this instance, although it looks like that is happening which is why this old wives tale has stuck around so long.