Stories create a rare pocket of shared attention. In a typical day, children receive lots of instructions and interruptions. Story time reverses that. The parent sits close, the pace slows down, and language becomes gentle.
This matters because the body learns from rhythm. Repeated bedtime reading helps children predict what comes next, and predictability is deeply calming.
Stories also offer emotional rehearsal. Children hear about bravery, worry, kindness, mistakes, and repair in a low-stakes format. That gives them language for their own feelings long before they can explain them clearly.