Reducing gender inequality is one of society’s greatest challenges and a top priority of the European Commission as reflected in its Gender Equality Strategy 2020-25. One of the UN Global Goal targets is ensuring women’s effective participation at all levels of decision-making in political, economic and public. Yet, only around a third of managers in the EU are women (2022 SDG statistics). Why? The objective of React2Success is to uncover how gender behavioural differences in reaction to success and failure under competitive pressure influence gender gaps in educational and career paths and, ultimately, unpack the mechanisms by which gender inequality persists. Providing causal evidence on gender gaps in reaction to performance shocks in competitive settings —such as job applications for leadership roles or high-stakes exams— remains challenging. In real-life settings, gender differences in preferences for competition result in self-selected samples, while in tournament-like lab experiments incentives often differ from real-world conditions. React2Success aims to fill this gap. I will take an interdisciplinary theoretically-driven Big Data approach by linking detailed population-level administrative records of both low-stakes high school and high-stakes university admission examinations with information on non-cognitive and long-term socio-economic outcomes from experimental survey data to: First, document gender gaps in response to competitive pressure in a real-life setting addressing concerns of sample-selection bias and external validity. Second, examine gender differences in reaction to success and failure in a high-stake competitive setting and shed light on the behavioural mechanisms at work. React2Success will also go beyond its immediate scope to establish the long-term socio-economic impact of these gender gaps and supply scientific evidence for devising cost-effective policies to tackle persistent equality issues in the allocation of talent.