“Everybody is afraid of something, but I outgrew my childhood fears. Just give your child some time, and I am sure she will grow out of it too.” Words like these are frequently reported by parents who bring their child to treatment of anxiety disorders. Although the statement is partially true - anxiety is a normal part of life, and some children outgrow their fears - it also shows that knowledge about anxiety and its detrimental effect on the child, family and society is lacking. Anxiety disorders are among the most common psychiatric disturbances in childhood with clinical levels of anxiety between 6-10%. Left untreated it increases the risk of academic and social failure as well as psychopathology in adulthood. The societal costs are significant. The development and maintenance of anxiety disorders involves a complex interplay among risk and protective factors in the child, parents and society. Different research traditions have focused on different factors in this complex equation. Attachment theory has provided insights into the impact of parent-child interactions on the child’s psychic development in longitudinal normal samples. Social learning theory and the associated treatment, cognitive behaviour therapy, has focused on e.g. emotional and cognitive factors in clinically anxious children and their parents. Unfortunately knowledge regarding the connections among child, parent, family and societal factors is sparse and research has yet to explain who will develop anxiety and why. The purpose of the present proposal is to take the field a step further, by merging theoretical perspectives and applying gold-standard methodologies, developed on both sides of the Atlantic, from both perspectives. The proposed work addresses the interrelation between anxiety disorders, emotion regulation, attachment, cognitions and behaviours in two studies: (i) a high-risk New York longitudinal sample; and (ii) a Copenhagen sample of clinically anxious children and their parents.