Phobia

A phobia is an irrational, persistent fear of certain situations, objects, activities, or persons. The main symptom of this disorder is the excessive, unreasonable desire to avoid the feared subject. When the fear is beyond one's control, or if the fear is interfering with daily life, then a diagnosis under one of the anxiety disorders can be made.

It is generally accepted that phobias arise from a combination of external events and internal predispositions. Some phobias such as arachnophobia and ophidiophobia however, may arise more easily due to an evolutionary trait that conditioned humans to fear certain creatures that could cause them harm. In a famous experiment, Martin Seligman used classical conditioning to establish phobias of snakes and flowers. The results of the experiment showed that it took far fewer shocks to create an adverse response to a picture of a snake than to a picture of a flower, leading to the conclusion that certain objects may have a genetic predisposition to being associated with fear. Many specific phobias can be traced back to a specific triggering event, usually a traumatic experience at an early age. Social phobias and agoraphobia have more complex causes that are not entirely known at this time. It is believed that heredity, genetics, and brain chemistry combine with life-experiences to play a major role in the development of anxiety disorders and phobias.

...More at Wikipedia 

Related Links:

• US National Library of Medicine
• Mayo Clinic

Recent Hope Cube Blog Entries For Phobia