The socio-economic achievement gap is prevalent in schools across the country. There are many high-poverty, high-performing schools that have been successful in closing this achievement gap. This study investigated 30 Illinois elementary school principals from high-poverty, high-achieving schools. Principals were given the Myers-Briggs Type Indicator and data was collected about school location, number of administrative jobs previously held, gender, race, and ethnicity of the principal. The personality types of the principals were compared to historical data on personality types of school principals. There were three findings in the study. Principals with the sensing-thinking-judging (STJ) type were most prevalent in the sample of high-poverty, high-performing schools. The rate of STJ and specifically ESTJ in the sample was higher than the historical data for principal personality type. Principals in their third or more administrative job in the sample had higher scores for extravert than those in their first or second job. More research is recommended including larger samples, samples including high schools, and comparison research with principals of high-poverty, low-performing schools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]