Anxiety Disorders result from a combination of family and biological influences. Studies suggest that young children who are temperamentally (at birth) shown to be shy or tentative in unfamiliar situations may be more prone to anxiety. Separation anxiety may develop after a significant stress or trauma in the child's life, such as a stay in the hospital, the death of a loved one or pet, or a change in environment (such as moving to another house or a change of schools). The fact that children with separation anxiety often have family members with anxiety or other mental disorders suggests that a vulnerability to the disorder may be inherited. Evidence suggests that anxiety can be learned, either through direct experience or observations of others.