This kind of topic always take me back to the popular debate among scientists. Nature vs nurture. The fear of crowd, as agoraphobia is often reffered to can be a product of genes as well as environment. A child that grows up in an isolated place is more likely to be agoraphobic even though he doesn't have the genes. Likewise a child purported to have agoraphobic genes might not display the tendencies if he grows up in an interactive environment.

So, who wins between nature and nurture?