From a Wikipedia article on brain lateralization. The emphasis is mine:
Hines (1987) states that the research on brain lateralization is valid as a research programme, though it has been applied to promote subjects and products far out of the implications of the research. For example, the implications of the research have no bearing on psychological interventions such as EMDR, brain training equipment, or management training. One explanation for being so prone to exaggeration and false application is that the left-right brain dichotomy is an easy-to-understand notion, yet is often grossly oversimplified and misused for promotion in the guise of science.
This is often known as right-brain mythology, and is associated with occult notions such as yin/yang, righteous and sinister, and day and night. The research on lateralization of brain functioning is ongoing, and its implications are always tightly delineated, whereas the pseudoscientific applications are exaggerated, and applied to an extremely wide range of situations.
http://en.wikipedia.org/wiki/Right_brain#Pseudoscientific_exaggeration_of_the_researchNonetheless, I think the last picture looks evil too.