This was a very clever study and a very cute result. In short: in order to test whether the increased attentiveness and distraction associated with phobias was related to an evolutionary advantage of quickly sensing threats, or if it was due to the increased emotional significance of, say, spiders to arachnophobes.
If increased attentiveness was a result of a need to detect threats, then arachnophobes would be distracted by photographs of spiders, but fans of Doctor Who would not be particularly distracted by photographs from Doctor Who. If increased attentiveness was a result of emotional significance, then fans of Doctor Who would be distracted by photos from Doctor Who just like arachnophobes would be distracted by photographs of spiders.
As it turns out, fans of Doctor Who who are not afraid of spiders are distracted by photographs of Doctor Who. The effect is less significant for Whovians than it is for arachnophobes, which could be due to some residual effect of threatening things being also more distracting than enjoyable ones, although the researchers suggest that could also be due to a greater familiarity or easy recognition of spiders as versus scenes from Doctor Who.
In any case, this was very cute. Read the whole paper!
I especially liked it as an example of how pop culture was used in science — in this case, the fact that it was Doctor Who that people were fans of was mostly irrelevant to the study; the researchers weren’t interested in Doctor Who as such. But they wanted something that a lot of people would have an emotional connection to — and so they chose pop culture. Which made me smile.