Causes

Phobias starts to develop in late childhood, adolescence, or early adult life in response to frightening event or situation. But, it's not always clear where phobias originated.
The cause of simple phobias is not always known. Occasionally a simple phobia can be traced to an earlier experience.The causes of complex phobias, like agoraphobia and social phobia, are unclear. Social phobias ma begin due to an anxious and intense experience in a social situation. Or it may be that your social confidence did not have the chance to fully develop past the normal stage of shyness of a young child.