==== Front Innov Aging Innov Aging innovateage Innovation in Aging 2399-5300 Oxford University Press US 10.1093/geroni/igaa057.2083 igaa057.2083 Abstracts Session 5715 (Symposium) AcademicSubjects/SOC02600 Ideal Levels of Prosocial Involvement in Relation to Momentary Affect and Eudaimonia: Exploring the Golden Mean Finley Kelsey 1 Axner Maria 1 Vrooman Katherine 1 Tse Dwight 2 1 Claremont Graduate University, Claremont, California, United States 2 The Chinese University of Hong Kong, Hong Kong, China 2020 16 12 2020 16 12 2020 4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”614 614 © The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract Aristotle believed that happiness and success result from cultivating virtue at the mean between deficiency and excess - the golden mean. Some evidence suggests there is a golden mean of hours spent volunteering, where well-being benefits are maximized. Our study examined potential linear and nonlinear functions in the amount of time spent in prosocial work (PSW) in a day on the outcomes of eudaimonia, high arousal negative affect, and high arousal positive affect in a sample of high-commitment volunteers and prosocial leaders. In addition to nonlinear functions, interactions were explored. For example, we found that those who spend less time per week in PSW experience less negative affect when they spend more hours per day in PSW; however, those who spend more time per week in PSW experience more negative affect when they spend more hours per day in PSW. Additional findings for positive affect and eudaimonia will be discussed.