Researchers are uncertain exactly what causes phobias. However, it is commonly believed that certain factors — likely in various combinations with each other — may increase the likelihood that a phobia will develop.
These factors include:
Research has shown that certain phobias may run in families. For example, twins who are raised separately in different locations may develop the same phobias. But at the same time, many people with phobias have no relatives with the condition.
Adults and children who move to countries where there is a language barrier may have phobias of socialization due to the embarrassment they feel.
The brain has special chemicals, called neurotransmitters, that send messages back and forth to control the way a person feels. Serotonin and dopamine are two important neurotransmitters that when “out of whack” can cause feelings of anxiety that can lead to phobias.
Anxiety and fear can be inherited. Just as a child can inherit a parent’s brown hair, green eyes and nearsightedness, a child can also inherit that parent’s tendency toward excessive anxiety. In addition, anxiety may be learned from family members and others who are noticeably stressed or anxious around a child. For example, a child whose parent shows immense fear of spiders may learn to fear spiders, too.
Life experiences (environment):
Real-life events that may or may not be consciously remembered can also cause phobias. A traumatic experience (such as a divorce, illness or death in the family) or even just a major life event like the start of a new school year may also trigger the onset of an anxiety disorder. Remembering an attack from a dog when you were younger may lead to a phobia of dogs. Being bullied in school when growing up can also lead to a social phobia as an adult.
More info (opens in new window): National Institute of Mental Health, February 13, 2008