Acknowledgements: We gratefully acknowledge all the CLIC Phase 1 Consortium members for their dedication and collaboration in this project. Our sincere thanks go to the external collaborators for their insightful contributions. We extend our appreciation to the student assistants for their crucial efforts. We also acknowledge our funding agencies and institutions for their financial support. Lastly, we express our gratitude to all individuals who provided valuable feedback and encouragement. We are fortunate to have collaborated with such exceptional individuals, whose collective efforts shaped the success of this research project. The complete list of consortium members, external collaborators, and student assistants can be found in the Appendix G in S1 File.Funder: National Research Foundation Singapore; funder-id: http://dx.doi.org/10.13039/501100001381BACKGROUND: Cognitive flexibility (CF) enables individuals to readily shift from one concept or mode of practice/thoughts to another in response to changes in the environment and feedback, making CF vital to optimise success in obtaining goals. However, how CF relates to other executive functions (e.g., working memory, response inhibition), mental abilities (e.g., creativity, literacy, numeracy, intelligence, structure learning), and social factors (e.g., multilingualism, tolerance of uncertainty, perceived social support, social decision-making) is less well understood. The current study aims to (1) establish the construct validity of CF in relation to other executive function skills and intelligence, and (2) elucidate specific relationships between CF, structure learning, creativity, career decision making and planning, and other life skills. METHODS: This study will recruit up to 400 healthy Singaporean young adults (age 18-30) to complete a wide range of cognitive tasks and social questionnaires/tasks. The richness of the task/questionnaire battery and within-participant administration enables us to use computational modelling and structural equation modelling to examine connections between the latent constructs of interest. SIGNIFICANCE AND IMPACT: The current study is the first systematic investigation into the construct validity of CF and its interrelationship with other important cognitive skills such as learning and creativity, within an Asian context. The study will further explore the concept of CF as a non-unitary construct, a novel theoretical proposition in the field. The inclusion of a structure learning paradigm is intended to inform future development of a novel intervention paradigm to enhance CF. Finally, the results of the study will be useful for informing classroom pedagogy and the design of lifelong learning policies and curricula, as part of the wider remit of the Cambridge-NTU Centre for Lifelong Learning and Individualised Cognition (CLIC)