The time has come. It’s the zombie apocalypse.

You’re approaching a zombie hoard with a group of several other brain-intact companions, and you need to figure out the best way to run past them. Where should you turn?

First, perhaps you should turn to social psychology.

There is an infamous parable, a now-classic staple in psychology classrooms across the country, about Kitty Genovese -- the woman who was supposedly murdered in Queens in front of dozens of onlookers who failed to do anything to help, each person assuming that the other bystanders would assume responsibility.1 This phenomenon is known as diffusion of responsibility or the bystander effect. Essentially, the larger any group gets, the less likely it is that any single person in that group will intervene or take action when confronted with any given situation, because each individual sees more other people around who could take responsibility or "pick up the slack," so to say.

Most of the time, when we talk about the bystander effect, we focus on its negative effects and implications, emphasizing the undesirability by providing suggetsions for how to reverse it and how to get help from a crowd when you need it. But, instead of focusing on those aspects, I’m going to take a slightly-less-common approach today in honor of Halloween — I’m going to discuss one way that you could potentially use your knowledge of the bystander effect to your (safe and legal) advantage.

The hypothesis I'm presenting here was first tested three years ago at the Run For Your Lives Zombie 5K, where I (and a few thousand others) attempted to complete a 5K course filled with volunteers who were dressed up like zombies and trying to steal our “lives” (aka flags on a belt around our waists). Sure enough, most of the runners attempted an obvious strategy: Attempting to run around the zombies, skirting off to the edge of the path and trying to dodge them as quickly as possible. The problem with this approach, however, is that the zombie closest to the edge clearly recognizes that it is his or her responsibility to take you down.

Instead, using my knowledge of social psychology, I tried a different, seemingly stupid tactic: Running directly through the middle of the pack. Sure enough, every time I tried to run around the pack, the zombie on the end reached out and grabbed one of my flags…but every time I sprinted straight through the middle of a giant pack of zombies, even though you would logically think that this would be the quickest way to lose your flags, the zombies all stood there and simply watched me run by, expecting one of the others to be the one to “take me down.”

Proudly posing with my remaining "life" (bottom left) after the race!

Lo and behold, I was able to make it through alive with one of my flags still intact, mostly thanks to my social psychology know-how (and a good amount of sprinting, to be fair).

So, if push comes to shove and it’s time for the Zombie Apocalypse2 (or if you simply find yourself wanting to compete in a Zombie 5K), use social psychology to your advantage: Run straight through the pack, instead of trying to dodge around it. Diffusion of responsibility can work to your advantage if you need to survive this spooky-scary weekend. And hey, if the zombies are coming after you for your tasty, super-smart, ultra-cunning braaaaaaaaaiiiiiiiiins, it only seems fair to turn the tables on them by manipulating theirs instead.


1. Although this story is a staple in Intro Social Psych classrooms around the country, more recent evidence has suggested that the “Kitty Genovese Case” may not have gone down exactly as it has been legacized. See this excellent post at the BPS Research Digest for more details. However, even those involved in debunking parts of the Kitty Genovese case have steadfastly claimed that the “bystander effect” is real and dangerous, and specific details about the Genovese case should not undermine this fact.

2. Yes, although Zombie 5Ks consist of living people with human reasoning capabilities, actual zombies would probably not follow the “rules” of human psychology. Let’s just go with it.


Darley, J.M., & Latané, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology, 8, 377-383.

Image Credits

Zombie group photo by Sven Kirsch via Pixabay

Zombie 5K image by Billie Weiss via Wikimedia Commons

Personal photographs

Post Notes

This piece was adapted from a July 2012 post on my original blog before joining Scientific American. You can see the original post here.