Regular HERD-fans will know that I've been repeatedly critical of the way we use market research, particularly survey and qualitative research (some practitioners seem to think I rarely go a day without a good dissing of MR), normally because of the poor witness each of us is to our own lives which renders the evidence supplied by such activities less than helpful.
So here's a simple rule of thumb that you might like to use:
If the thing you're interested in (the behaviour or engagement with that kind of issue) is spreading through social influence then don't bother the punter with your questions.
It's only if – as classical economics and many of our 'commonsense' rule of thumb "I'm-just-a-practical-fella" kinds of models assume – individuals are actually choosing independently of each other that you might find asking them what they like about the thing or what they feel etc of some use.
In other words, sort the influence bit out first and then and only then think about whether anything like asking a questionnaire is appropriate.