Looks like a skewed survey. Note they the people who were polled were mostly American Christians; hardly a group known for its open-mindedness toward anyone who thinks or acts differently from what it considers the norm. If the same sort of people were selected in the UBC study, then the study completely lacks credibility. Tell you what - let's have a study showing how atheists rate fundamentalist Christians; somehow I don't think the results would be much different.
In the first study they had 351 participants, the composition was 59% female, and the breakdown of reported religious affiliation was 67% Christian, 1% Jewish, 3% Athiest, 4% Agnostic, 17% None, and 9% Other. Of all participants, 14% answered 'No' to belief in God.
That's not too far off from what most surveys find for prevalence in America, generally Christianity makes up 59.9 to 76.0%, unaffiliated, which includes atheists and agnostics is about 15.0 to 37.3%, and Judaism 1.2 to 2.2%.
The second study was of undergraduate students at UBC, who complete surveys in the Psychology Human Subject Pool for extra credit. There were responses from 1,153 students, for studies 2-6. The demographic information for this group was reported as:
In terms of religious backgrounds, this is a very diverse group of
students. In descending order of frequency, our participants report
religious affiliations as Christian (34%), None (16%), Nonreligious
(12%), Agnostic (11%), Atheist (9%), Other (7%), Buddhist
(7%), Muslim (3%), and Jewish (1%).
This is also an ethnically heterogenous population from which
to sample: East Asian (49%), Caucasian/White (30%), Other/
mixed (7%), South Asian (6%), Southeast Asian (4%), Middle
Eastern (2%), Hispanic/Latino (1%), and African (<1%).
Here's the whole paper from Gervais' faculty webpage :
http://www2.psych.ubc.ca/~will/Gervais%20et%20al-%20Atheist%20Distrust.pdf