Chapter Seven, for example, provides a good discussion of blind spot #6: trapped by categories. First an example from Ellen Langer's book Mindfulness provides a way into the discussion. "Imagine that a wealthy man who is part of a scavenger hunt rings your doorbell in the middle of the night. He asks if you have the final item on his list, a piece of wood that measures about three-by-seven feet." He says he will pay you $10,000 for it. You think what could I find that would meet those criteria? Most of us wouldn't realize that we were standing right next to the needed item: the door. Too often we are "trapped by categories" and so fail to see new and unique ways of using things. As Van Hecke argues "classification flattens our perception of individuals" as well as of things and can lead to a diminished understanding and appreciation of the world around us.
http://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=3827&cn=396