Children who dont feel safe in infancy have trouble regulating their moods and emotional responses as they grow older. By kindergarten, many disorganized infants are either aggressive or spaced out and disengaged, and they go on to develop a range of psychiatric problems.23 They also show more physiological stress, as expressed in heart rate, heart rate variability,24 stress hormone responses, and lowered immune factors.25 Does this kind of biological dysregulation automatically reset to normal as a child matures or is moved to a safe environment? So far as we know, it does not. Bessel A. van der Kolk, The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma

The Body Keeps the Score by Bessel van der Kolk