The popular zombie fad according to a researcher is a reflection of unhappiness and dissatisfaction in society.

A Clemson university professor Sarah Lauro believes the popularity of zombie films and TV shows in recent years isn't harmful or a random fad but part of a historical trend that mirrors society's general dissatisfaction as well as economic chaos.

Lauro studied the zombie phenomenon for her doctoral degree at the University of California at Davis.

"We are more interested in the zombie at times when as a culture we feel disempowered," Lauro told The Associated Press. "And the facts are there that, when we are experiencing economic crises, the vast population is feeling disempowered."

She kept track of zombie films, TV shows and video games however research primarily focuses on the "zombie walk," a mass gathering of people who, dressed in the clothes and makeup of the undead, stagger about and dance.

"I hate violence," she said. "I can't stand gore. So it's a labor, but I do it."

She added, "Either playing dead themselves ... or watching a show like 'Walking Dead' provides a great variety of outlets for people."

Lauro has said that such occurrences started in 2003 in Toronto, and their popularity spread through the following years.

"It was a way that the population was getting to exercise the fact that they felt like they hadn't been listened to by the Bush administration. Nobody really wanted that war, and yet we were going to war anyway," Lauro said.

Lauro describes "zombie walks" had been documented in at least 20 countries as of 2012, with more than 4,000 participants gathering at the New Jersey Zombie Walk in Asbury Park in October 2010, according to Guinness World Records.

"If you were to ask the participants, I don't think that all of them are very cognizant of what they're saying when they put on the zombie makeup and participate," she said. "To me, it's such an obvious allegory. We feel like, in one way, we're dead."