满月 (mǎnyuè), or Full Moon, is when a baby turns 30 days old. In China, it’s tradition to cut a baby’s hair for the Full Moon celebration.
Before our son turns 30 days, my mother-in-law sends my husband a message: “Once you’ve cut the hair, put it into a cloth. Put the cloth with the hair underneath the baby’s pillow. This way, he won’t be as easily startled anymore*.”
*What my mother-in-law is referring to is the Moro reflex. The Moro reflex describes the sudden spreading out and unspreading of arms that is often followed by crying, a reflex most babies have until they are 4 or 5 months old. It is believed to be triggered by a sudden feeling of falling.