Is fundamentalism a religious movement or a psychological disorder?
The four most studied fundamentalisms by scientists and scholars are the Jewish, Christian, Muslim, and Hindu variations of the phenomenon. There is a wide range of informed opinion about fundamentalism, but most people find fundamentalism remarkably similar regardless of which religion it is associated with.
There is indeed some scientific support for the possibility fundamentalism is more of a psychological disorder than a religion or religious movement. For instance, see Chapters Three (page 75), Four (page 106), and related pages in Robert Altemeyer's introduction to authoritarianism, which can be found
here (pdf).
As for myself, I believe calling fundamentalism a "religion" might be like calling Bipolar Mood Disorder a "philosophy". The evidence seems headed in that direction.
Your thoughts?*
*Please read Chapters Three and Four in Altemeyer before responding -- unless you are very familiar with the science on this subject.
EDIT: As I remarked to Dave in a post in this thread: It intrigues me that fundamentalism might be characterized as a religious movement piggybacking on a psychological disorder.
EDIT: To clarify, I am suggesting that -- at the very least -- fundamentalism is most likely significantly more strongly associated with dysfunctional thinking and/or moods than is, say, mainstream Catholicism, Reform Judaism, etc. Beyond that, I suspect fundamentalist ideologies tend to be especially attractive to people suffering from one or more mental illnesses and tend to be just as unattractive to relatively healthy people. In other words, I think it is likely more fundamentalists are mentally ill than members of similar groups, and likely that fundamentalism tends to attract mentally ill people and tends to repulse mentally healthy people.
EDIT: Try thinking of "mental illness" as "thoughts and moods that are conducive to, and/or symptomatic of, dysfunctional behavior."