Confirmation Bias and Expectations Influencing Perceptions: A Micro-Case Study

October 23, 2013

As a skeptical investigator with a degree in psychology, I often encounter (and discuss) people whose expectations have colored their perceptions. This is often the case with ghost hunters, UFO buffs, Bigfoot and lake monster searchers, and others. We often see what we expect to see, whether it's there or not. Of course everyone does it, including me. Here's a personal account of my recent experience:

Last week I went to Jiffylube for an oil change, and as part of their service they wash the windows and rifle through your change box. As I waited I glanced out at my car, where a worker was cleaning the window. About fifteen minutes later they finished and as I left the parking lot I looked down and noted that they had also cleaned the dashboard window (where the speed, RPM, etc. is). I made a mental note that that was nice of them, since it gets dusty here in New Mexico.

I ran a few more errands, and a few minutes later as I drove perpendicular to the sun I was shocked to see that-exactly contrary to my expectations and direct observation-the dashboard window had not cleaned it after all. It was not filthy, but it was clearly dusty and had been untouched by the Jiffylube workers. I probably had subconsciously assumed they had cleaned it along with the windshield, and when I glanced down at it, it appeared to be cleaned-so clean, in fact that I even remarked to myself how thorough their service was!

My expectations clearly influenced my perceptions, and I'm not the only one. It probably happens to all of us on a regular basis, but we don't notice it, or if we do, we think little of it. However these are exactly the same processes underlying many paranormal eyewitness claims. As the famous skeptical dictum goes, if you believe you cannot be fooled, you have already been fooled.