Academic associations define the scientific standards and affect individual academic careers within a discipline. The European Association of Social Psychology (EASP) was founded in 1966 to become an association for all social psychologists in Europe. However, this was unattainable during the Cold War, and more subtle obstacles, such as women's underrepresentation in academia, prevented EASP from due representation of all social psychologists. Social psychological theory offers insights into why social hierarchies are maintained and how they can be dismantled. We used the case of EASP to analyse challenges to creating a diverse and inclusive association by analysing membership data, participation, distinction and influence throughout the organisation's history and conducting a more in-depth analysis for the 2011-2017 period.We found a glass-ceiling effect for women and a persistent underrepresentation of non-Western European scholars on all levels. We conclude that increasing diversity requires more fundamental changes to overcome structural inequalities.