The other day I was out for a mountain bike ride in a nearby wilderness area. As I neared the woods, I noticed a police SUV stopped by two bikers. It looked like the police were talking to them about something, then the car took off down a trail in the direction of a dense part of the forest. When I reached the bikers that had been stopped by the police car, they flagged me down and told me that a bear had been spotted in the area. The police asked them advertise the presence of the bear to other bikers.

The couple seemed a bit excited. They explained that they were new to the area and asked if bear sightings were common. I told them that I had been riding in the area for fifteen years and had only seen bear twice. I thought this would reassure them that bear were rare. They took it as confirmation that a bear was a very real threat and took off in the opposite direction. I thought I would explore a bit more and went down the trail in the direction of the police and presumably the bear. I didn't go very far, when I realized that there was no one else on what would normally be a busy trail on a nice Sunday afternoon. Obviously, all the bikers in the area had heeded the warning. So I decided not to press my luck either and left the area.

Heading in the other direction, I decided to follow a trail that runs along side a lake. But to my surprise, there was a big metal gate blocking the trail with a very official looking warning sign advertising that the park authority had closed the trail due to unsafe conditions. I stood there for a moment, and noticed that mountain bikers had been bypassing the gate and using the trail in spite of the warning. I waited a moment longer and could see people heading in both directions on the trail. So I ignored the sign and biked down the trail.

As I biked along the trail, I didn't see anything that looked dangerous or would cause the trail to be closed. The only thing I could think of was a couple of spots where it looked like some mud had slid down a cliff during a heavy rain. This would have made the trail very slippery in those spots when it was wet. Probably someone had been riding there in the rain, slid and hurt themselves, and sued the park authority. But it had not rained in at least a week and the trail was safe. Leaving the gate up and declaring the trail closed accomplished nothing as people soon learned that there was nothing to fear.

As I continued my ride, I thought about what these two incidents taught me about advertising risk. Two powerful ways to motivate human behaviour are authority and social proof. When risk is communicated, an authority of some sort often delivers the message or is cited by whoever is delivering the message. This makes sense, especially because it is often the authorities and experts who identify the risk in the first place. But communicators need to remember that social proof, the phenomenon of looking to others to guide appropriate behaviour will override authority. Part of a risk communication strategy must anticipate how people are going to react and plan the resulting social proof as a part of the risk communication plan.