separation anxiety

n. The normal state of alarm and arousal with nonspecific fears that children experience when faced with separation from their parent or other caregiver from the ages of 6 months to 3 years of age. It is most intense in the second 6 months of life and persists at lower levels beyond 3 years. Attachment theory deems this to be part of the attachment system which helps children maintain proximity to their caregivers and so increase the likelihood of their survival.