The invisible gorilla

March 21, 2012
Issue 4

Do you know what you’re missing? You might be surprised. A friend forwarded an e-mail to me, sometime in 2002, with the subject line, “I don’t normally forward these, but you HAVE to see this.” I clicked on the link and started watching a video of two teams passing a basketball. The scrolling text below the video told me to count the passes made by the team in the white shirts, while ignoring the passes made by the team in the black shirts. I focused intently on the white-shirted team.

Do you know what you’re missing? You might be surprised.

A friend forwarded an e-mail to me, sometime in 2002, with the subject line, “I don’t normally forward these, but you HAVE to see this.” I clicked on the link and started watching a video of two teams passing a basketball. The scrolling text below the video told me to count the passes made by the team in the white shirts, while ignoring the passes made by the team in the black shirts. I focused intently on the white-shirted team.

I was incredulous. As a dentist, I believed my attention to detail was better than average. Surely this was some video sleight of hand and not a mistake on my part. But I had fallen into the trap of Harvard psychologists Christopher Chabris and Daniel Simons, who created the video to test selective attention. Their 1999 research showed 50% of people would miss the gorilla. They found no pattern in age, gender or education level to explain who saw it and who didn’t. What they did find was people missed the gorilla specifically because they were not looking for anything out of the ordinary. Our brains are wired to expect the expected, and as dentists we are trained to do the same. As the adage goes, “If you hear hoof beats in Georgia then you should expect a horse” rather than a zebra-or, in this case, a gorilla.

Chabris and Simons dubbed the phenomenon “inattentional blindness.”  In their 2010 book, The Invisible Gorilla and Other Ways Our Intuitions Deceive Us, they build on that research, sharing some incredible examples of how our memory and attention are not completely reliable. We think we see the world as it is, but the authors tell us “our vivid visual experience belies a striking mental blindness.”  This is not a bug in our software, so to speak, but rather an inherent limitation. Because the brain is a closed system, it has finite resources. We unconsciously allocate those resources, choosing what to “see” and what to ignore.   

This blindness can affect the dental practice as well. Feeling rushed and overly busy, we walk into a hygiene check, look at the bitewings and completely miss the decay. Similarly, a dentist who is completely focused on the practice’s “bottom line” numbers may overlook the fact that the entire office is not functioning at its best and is slowly coming apart at the seams.  

Chabris and Simons cite many examples of the limitations of our brains, but they do not propose a remedy for this blind spot in our attention. While each story is interesting, the book lacks an overarching story line to tie the vignettes together.  

Nevertheless, the findings make us aware of our own limitations. We can create processes to compensate for these blind spots and reduce error. Having your hygienists review bitewings and comparing their findings with your own is a good way to reduce the chances of missing an important finding. Periodic team sessions with a practice manager may help the dentist take a more global view of the practice, thereby raising team morale and increasing overall production. Such practices take into account the holes in our attention and close them to the gorillas that we can all miss.

4 stars out of a possible 5.