Why Do Babies Suck Their Thumb? The Science Behind It

why do babies suck their thumb

Thumb sucking is one of the earliest self-soothing behaviors a baby develops, and it starts before birth. Ultrasound images have captured fetuses sucking their thumbs as early as the first trimester, which tells us this is a built-in reflex rather than a learned habit. After birth, the behavior continues because it meets real needs: comfort, … Read more