Two suggestions
This might be an interesting way to test the theory that some people are born naturally more prone to develop phobias than most:
Do you have any irrational fears not to do with people, however mild or severe?
None
One or two
Between three and five
More than five
Another one could be:
Which of these best describes how you think others see you?
Cold and unemotional
Touchy and melodramatic
Fawning and desperate
Always miserable
None of the above, but mainly negative things
None of the above, but mainly positive things
I really don't know