As I read through the textbook, I found myself drawn to the research surrounding the 10% myth. It is one of the most widely known psychology rumors started by William James, who stated that we don't use all of our "intellectual potential", a thought that was greatly misconstrued to mean that we only use 10% of our brains. Luckily, Karl Lashley disproved this in the 1920s, but until that point it was an extremely widespread myth.
So what was the impact of this long-held belief?
Lobotomy procedures are one example of the impact of this belief.
The procedures consisted of cutting out part of the prefrontal cortex. However, the creators of this procedure, Egas Minz, failed to realize that if one part of the brain is removed, the rest of it is affected as well. If Egas Minz had known that we use all of our brain and that the parts are interconnected, would he have gone through with it? Would the lives of thousands of lobotomy patients have continued normally? We may never know, but it is definitely something to imagine.