Hemisity refers to binary thinking and behavioral style differences between right and left brain-oriented individuals. The inevitability of hemisity became clear when it was discovered by magnetic resonance imaging (MRI) that an anatomical element of the executive system was unilaterally embedded in either the right or the left side of the ventral gyrus of the anterior cingulate cortex in an idiosyncratic manner that was congruent with an individual’s inherent hemisity subtype. Based upon the MRI-calibrated hemisity of many individuals, a set of earlier biophysical and questionnaire hemisity assays was calibrated for accuracy and found appropriate for use in the investigation of the hemisity of individuals and groups. It had been reported that a partial sorting of individuals into hemisity right and left brain-oriented subgroups occurred during the process of higher education and professional development. Here, these results were extended by comparison of the hemisity of a putative unsorted population of 1,049 high school upper classmen, with that of 228 university freshmen. These hemisity outcomes were further compared with that of 15 university librarians, here found to be predominantly left brain-oriented, and 91 academically trained musicians, including 47 professional pianists, here found to be mostly right brainers. The results further supported the existence of substantial hemisity selection occurring during the process of higher education and in professional development.