Um. I suppose that some other food-eating behavior is also signaling, but I don't think that the majority if non-organic food eaters are doing it because they conceive of themselves as people who don't eat organic food and want to show off that fact. And I'm rather suspicious of the idea that not eating a selection of foods is signaling as a general rule. Like, someone could eat Italian food as a form of signaling (especially if they themselves identify as Italian) but someone who doesn't eat Italian food is probably not doing it because they think of themselves as someone who "doesn't eat Italian" and wants to signal that fact.
I suppose there are probably people out there who don't eat organic as a way of showing affiliation, but I don't think that encompasses any significant portion of those people who do not eat organic food.
I've been wondering whether there's any solid evidence that organic food is healthier than conventionally produced food-- the arguments I've seen on the subject have been theoretical/aesthetic.
I'm interested in anything in the range from personal stories to scientific studies, but would prefer to avoid extremely general arguments or claims that people who prefer one or the other are demonstrating character defects.
Edited to add: Thanks for the replies. I'm hoping for experiments which test the effects of food produced in various ways on organisms, especially multi-cellular organisms. It was interesting to find out that plants which have to fight off insects for themselves have more mutagens.
The mutation experiment is very cute, but it leaves out the possibility of damage that isn't related to mutation-- for example, hormonal effects. Also, if it's done on a standard bacteria acquiring the ability to make a particular nutrient, this might not be a test for mutation in general.
I realize experiments on organic vs. conventional would be difficult, especially if you're tracking human health. It would be very hard to avoid confounding factors like other lifestyle factors and income.
"Conventional food" is actually a large blob of a concept-- different pesticides, fertilizers, etc. are used on different foods at different times, so finding out what people are actually exposed to would be difficult.