The study sought to determine effects of leadership activity on emotional intelligence in preadolescents. Ninety-two Central California Valley sixth grade students in two schools and four classes were assessed on emotional intelligence. Treatment and comparison groups were identified. A Two-Way Repeated Measures ANOVA examined change over time with respect to treatment, main effect, and interactions. Questions guiding the investigation were: (1) Is pre-adolescent emotional intelligence affected by leadership activity? (2) Will students of lower SES improve emotional intelligence scores as a result of leadership activities in distinctively different ways when compared to those students of higher SES, as measured by the Mayer, Salovey and Caruso, Emotional Intelligence Test: Youth Version (MSCEIT:YV)? Findings revealed partial support for these predictions. Main effects reveal significance for 5 out of 7 areas with treatment group generating greater means, and SES groups approaching significance for 2 out of 7 areas. Results suggest that leadership activity may be an important vehicle for improving emotional intelligence in schools, students of lower SES may benefit more than students of higher SES, and assessment instrument, regarding vocabulary, for younger populations may require revision. [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.]