I think this subject is one where most people make deeply emotional decisions. In general, people cannot be reasoned out of positions they did not reason themselves into, and food is definitely not an exception. Food is too intimate and sensitive to most people.

What I've found is that when you use reason and evidence to assuage the particular concerns (certainty, safety, pesticide use), they are generally replaced by others. Distrust of Monsanto, agricultural monoculture, IP law, and so on. What do you think happens when you address them all? Show safety studies, bring up golden rice, and so on?

What you don't get is large masses of people changing their minds. What you do get is people suddenly deeply uncomfortable with the entire conversation, because their fig leaves are gone but their emotions haven't changed. Then someone says that you sound just like those people who work for Monsanto - which has happened to me today on HN.

Yes, I'm a cynical bastard.