Contagious politics

With less than three weeks to Election Day, political signs are everywhere, with more popping up daily. Ever wonder why signs tend to be clumped in yards on one end of a block, or why next-door neighbors will publicize their disagreements to strangers driving by? If it seems that there's something more than politics going on, you're right.

Putting out a sign can be a powerful provocation to others — to rally to your candidate, or to declare their opposition. The phenomenon is called "goal contagion," explains Art Markman, a cognitive scientist at the University of Texas and Psychology Today blogger.

When someone puts out a political yard sign, the people who see it immediately understand the goal. This action leads others to be more likely to want to announce their own preference. This desire is likely to be particularly strong for one's neighbors, says Markman, because they see the sign every day.

You can also see the contagion at work in this story: When business leaders became vocal in their opposition to County Commission candidate Karl Peterjohn, "It inspired a backlash for Karl," Darrell Leffew told The Wichita Eagle. He recently put six pro-Peterjohn signs in his yard.