Who would ever imagine that most of us could watch a video of six students passing basketballs without noticing something as obvious as a person in a gorilla suit walk into the middle of this small group, stop and face the camera, beat themselves on the chest and then walk off again. Yet most people who have seen this classic film clip do not spot the gorilla.
One of the great benefits of having real people as part of the safety systems on which we rely is that we can be great at spotting things which are out of the ordinary. On the other hand, one of the disadvantages of relying on humans is that we can sometimes be rubbish at seeing things, even when we’re looking at them.
We call this inattentional blindness. It does not result from any problems with our eyes, but from the wider process that allows us to see the world around us. Our brain frequently fills in gaps and edits out objects. Because this is all done subconsciously we find it hard to reconcile. We all believe that we would see the gorilla or notice other obvious changes.
The same group from Harvard University that ran the original gorilla experiment developed another, similar experiment to test how much attention we pay to the world around us. Subjects were stopped at random and asked for directions by a stranger. Once engrossed in the conversation they were briefly interrupted during which time the person to whom they were giving the directions was swapped for a second person. Surely that would be really obvious, yet nearly half of the subjects did not notice that they were talking to a different person.
Inattentional blindness can be very dangerous and often accounts for serious accidents, with many examples seen on our roads. Car drivers frequently fail to see cyclists and motorbikes, because they are actually looking for car-shaped and car-sized objects.
I experienced this at first-hand recently whilst out riding my bike. I was on a quiet, main road when I saw a car approach a junction ahead on the left, intending to turn right. I saw the driver look down the road in my direction and then concentrate on looking up the road away from me, which was harder for him to see due to a building obscuring his view. I somehow knew that he hadn’t seen me so I anticipated that he would pull out across my path. This is exactly what he did, exactly at the point that I would have gone under his front, right wheel had I not already taken evasive action. I should also say that it was clear daylight and I was wearing bright green and white kit, so I shouldn’t have been that hard to see – just like it shouldn’t be that hard to see a gorilla walk through a group of people playing basketball!
We would do well to remain aware of this common human weakness in the workplace. It is so easy to miss an obvious hazard particularly if we focus on some other aspect of the task. Luckily we often do not work in isolation so we have the opportunity to look out for each other. If you see a really obvious hazard, do not assume that your workmate has seen it. It is important to speak up and point it out. The worst that can happen is that they will tell you they had already seen it – but you might prevent an accident.
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