A sack-hauling time traveler from the 21st century lands in an Irish potato field in 1849, just before a terrible famine, and asks: If you thought genetically modified potatoes could avert late blight disease, spare a million countrymen from starvation and keep another million from emigrating off the Emerald Isle, would you plant these newfangled spuds?

Fast forward to the Internet Age, when communication researchers ran 859 U.S. grocery shoppers through a similar thought experiment: Half the subjects in an online survey read the story of the 1850s Irish Potato Famine, learning the potential impact of fungal Phytophthora infestans on potato and tomato crops today. The other 400-plus pondered generic plant disease, with no mention of specific crops or historic famines.

"Stories of the Irish Potato Famine were no more likely to boost support for disease-resistant genetically modified crops than were our generic crop-disease descriptions," said Katherine A. McComas, professor and chair of Cornell's Department of Communication in the College of Agriculture and Life Sciences.

"Preconceived views about risks and benefits of agricultural genetic engineering - and perceptions about the fairness and legitimacy of the decision-making process - these things matter most," McComas said.

With co-authors John C. Besley (Michigan State University) and Joseph Steinhardt (Cornell), McComas will publish study results as "Factors influencing U.S. consumer support for genetic modification to prevent crop disease" in the July 2014 journal Appetite - right about the time airborne P. infestansspores are drifting through home-garden tomato crops.

"If you think genetically modified crops are dangerous 'frankenfoods' and/or that crop disease is best controlled with chemicals - if you suspect federal regulators care more about Big Ag's interests than your family's, thus the whole game is rigged - plaintive tales of historical famines won't change your mind about genetic modification for disease resistance," McComas said.