Separation anxiety is when the toddler feels distressed when separated from the primary caregiver – mostly mothers. It could start at 9-10 months of age and tapers off by 18 months. By 3 years of age, most children can accept the temporary absence of their mother or primary caregiver.
This anxiety develops when the child’s sense of self starts developing and they also have an understanding of object permanence, i.e. the caregiver continues to exist when not in view. They express their separation anxiety by crying in their absence or being clingy to the parent, following them around, and preferring them over others.
In a room of people, the toddler uses the parent as the secure base from which they explore around in the room and come back again and again to the parent.