12/19/2025
The American Academy of Pediatrics now warns that sleep training before 12 months can disrupt attachment and nervous system regulation. The concern is not parenting style but biology. Babies’ brains are still wiring safety signals through proximity.
In the first year, infants cannot self-regulate. Their nervous system relies on co-regulation with caregivers. When stress rises, closeness to a parent helps settle the amygdala, lower cortisol, and signal safety. Room-sharing is a natural way to provide this support.
Sleep training too early teaches babies to manage stress alone before their brains are ready. Calm is not learned by isolation under stress. Instead, infants need repeated, responsive soothing so regulation becomes internalized over time.
Parents who previously sleep trained are not failing their children. They acted on the information available in a culture that often prioritizes independence over developmental readiness. Understanding the science changes how we view early sleep strategies.
This research emphasizes that proximity wires safety. Babies learn calm through closeness, not isolation. Early care that meets stress with support builds secure attachment, emotional regulation, and lifelong resilience.