The quantitative nonexperimental correlational study examines principals' attitudes towards intelligence and inclusion and the academic growth of students with disabilities. Additionally, the study comparatively examined principals' attitudes toward intelligence and inclusion across 11 demographic factors. The Theories of Intelligence Scale -- Other Form (TIS) and the Principals' Attitudes of Inclusive Education (PATIE) provide insights into principals' attitudes toward intelligence and inclusion for 149 public school principals across Ohio. The study utilized parametric methods of Pearson correlation, t-test, ANOVA, and post-hoc Tuckey HSD and nonparametric methods of Kendal Tau-b correlation, Mann-Whitney U test, Kruskal-Wallis test, and post-hoc Dunn's test. Findings show no relationship between principal intelligence attitudes or inclusion attitudes and academic growth. A small positive correlation existed between principal intelligence attitudes and principal inclusion attitudes of inclusive education (IE), implementation issues (II), inclusion benefits and level of disability (IB), and excluded students (ES). Furthermore, the study revealed inconclusive results for evaluating differences in principals' attitudes towards intelligence and inclusion across demographic factors. Future research should include a larger sample and qualitative methods to determine the justification of attitudes. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]