1. The idea that people rely on a preferred mode of cognitive processing that is linked to predominant activity of either their left or right cerebral hemisphere.

Individual hemisphericity was erroneously thought to be located somewhere on a gradient between right and left brain dominance with most people being intermediate.

2. The bias in thinking orientation, behavioral style, and personality resulting from the inherent laterality of one's sole Executive system within the asymmetric bilateral brain.

Thus, depending upon which brain side "the one and only you" inherently is located, someone is either a left or a right brain oriented person.