The human brain is lateralized, different functions being housed in each hemisphere. Several assumptions which are mistakenly considered fact by researchers include: (1) the left hemisphere is for rational functions, while the right is for intuitive functions; (2) the hemispheres do not interact as well with each other as they should; (3) the use of one hemisphere tends to depress the use of the other until one can become dominant; and (4) hemispheric dominance is probably a cultural phenomenon. Evidence has shown that measures used for assessing dominance and the assumptions they fostered, are suspect. The two-brain theory is of little importance in educational planning. Much concern for educating both sides of the brain is based on the supposition that one hemisphere could languish in ignorance while the other was enlightened. This is a naive supposition; lateralization is part of a complex interweaving of processes. Neurological research may have a profound effect on education in the future. (DWH)