Sarah Lauro, a visiting assistant professor at Clemson University in South Carolina, says there's a correlation between the popularity of zombies and unhappiness in society.
"Zombie walks," the name given to groups of people that get together styled like the undead, first rose to popularity in Toronto in 2003 and 2005, when anger and dissatisfaction escalated over the Iraq War.
"Some do it to make visible their dissatisfaction with a government they feel isn’t listening to them or an economic system that makes them brain-dead consumers," Lauro said. "Some do it as a kind of exercise of community, just to show how the collective can be organized and made to participate in an event without any ties to commercialism; many have no idea why they do it, but some play dead, one supposes, just to feel alive."
Lauro, who has spent a decade studying undead culture, pointed to the popularity of the genre during the Great Depression in the 1930s, when workers suffered in a struggling economy, the Cold War and the threat of nuclear holocaust, and even the space race.