Research suggests that good sleep supports your baby's brain development, memory, language skills, and physical growth. However, the evidence on exactly how much sleep affects development is still mixed—some rigorous studies show clear benefits while others don't show the same connections. What we do know is that well-rested babies tend to develop stronger cognitive and motor skills. The bottom line? Prioritizing consistent sleep habits matters, but don't stress if your baby's sleep isn't perfect. Additionally, if autism or ADHD runs in your family, research suggests paying attention to nighttime sleep patterns matters—poor sleep at 14 months was linked to later developmental concerns. If your baby struggles with frequent wakings, it's worth discussing with your pediatrician.