I'm half way through reading
The Authoritarians by Bob Altemeyer, which is available free online in PDF format.
Chapter 4 of the book addresses fundamentalists and evangelicals. There's more than enough fodder there for multiple threads in the R/T forum.
One topic that stood out for me as worthy of mention here is the discussion of zealotry in Altemeyer's book, and the characteristics of fundamentalism. Altemeyer does not directly address the idea of "atheist fundamentalism", but if you read Chapter 4 of his book (and better yet, the whole book leading up to that point), I think you'd find the idea that vocal atheists and religious fundamentalists are just "the same thing with different dogma", a viewpoint popular among a number of people who post in this forum, very hard to support.
Particularly telling is the large difference between how fundamentalist Christians reacted to the notion of organized prayer and teaching of Christianity in public school, with a majority in favor, and "active" atheists (members of atheist organizations, not mere self-described atheists), with a majority opposed.
There's a test given in this book used to measure zealotry, which I'll show below, but I'd like to introduce this with the same caveat the author gives for similar tests earlier in the book: take any personal, individual score with a very large grain of salt. The strength of these scores only really comes out in statistical sampling, where individual differences in reactions to the phrasing of questions and treatment of numeric scales tends to average out.
Your own personal score might be interesting to you, and comparing scores might be fun, but it's at best a very crude measure of your own actual zealotry. With that said, consider whatever religious or philosophical outlook is most important to you in your own life, and respond to the following twelve questions using this scale:
..........0 = Not at all true of me
..........1 = Slightly true of me
..........2 = Mildly true of me
..........3 = Moderately true of me
..........4 = Decidedly true of me
..........5 = Definitely true of me
..........6 = Very definitely true of me
1. This outlook colors and shapes almost everything I experience in life.
2. I try to explain my outlook to others at every opportunity.
3. I am learning everything I can about this outlook.
4. I think every sensible person should agree with this outlook, once it has been explained.
5. I get excited just thinking about this outlook, and how right it is.
6. It is very important to me to support the leaders of this outlook.
7. Nothing else is as important in my life.
8. It angers me that certain people are trying to oppose this outlook.
9. No other outlook could be as true and valid.
10. It is my mission in life to see that this outlook becomes “No. 1" in our country.
11. This outlook is the solution to all of humanity’s problems.
12. I am very committed to making this outlook the strongest influence in the world.
The author says the average total score is about 10-20. Fundamentalists score on average about 40 -- "No other group comes close to being as zealous".
Me? I certainly scored on the high side with a 29, with the scientific method being the particular "outlook" I had in mind. I'd attribute that high score not so much to belief in my own rightness as to strong feelings about the lack of reliability of non-scientific approaches, preferring scientific doubt strongly over religious certainty, and fear of the harm that non-scientific irrationality could bring to civil society and the world at large.