Dr. Flett is recognized globally for his seminal contributions to research and theory on the role of perfectionism in mental and physical health, and more recently, his foundational work on the psychology of mattering and its role in well-being and health. He is a member of the Canadian Psychological Association and in 2024/2025 he was named the Honorary President of the Canadian Psychological Association. He is also a Fellow of the Association for Psychological Science, which has cited him earlier in his career as one of the top 25 most productive authors in psychology. Dr. Flett is also the co-creator of numerous self-report measures assessing perfectionism and mattering (e.g., Anti-Mattering Scale, the Fear of Not Mattering Inventory).

Dr. Flett is extensively engaged in knowledge translation and exchange. His work has received widespread attention and has been the subject of numerous media stories, including coverage on CTV, CNN, and the BBC and in Scientific American, the Atlantic, the New York Times, the New Yorker and the Washington Post. His engagement includes several podcast appearances and appearances on CBC Radio and National Public Radio and most recently, on the Oprah Winfrey podcast on mattering in January 2026.

Finally, reflecting his commitment to community issues, Dr. Flett has received the Community and Leadership Award, Toastmasters International, District 60. He has also received the City of Mississauga Certificate of Recognition for "Outstanding Commitment to the Community” and the Peel District School Board Award of Excellence for Community Service.

Part I Introduction and Significance in People's Lives

1. Introduction

2. Life Stories of Mattering and Anti-Mattering: A Narrative Perspective

Part II Definition, Conceptualization, and Assessment

3. Mattering: Definitional Considerations and Historical Advances

4. Mattering as a Psychological Construct

5. The Assessment of Mattering

6. The Development of Mattering

Part III Mattering in Positive and Negative Adjustment

7. Mattering in Positive and Negative Adjustment

8. Mattering Versus Not Mattering in Mental Illness: Associations With Anxiety, Depression, Suicide, and Personality Dysfunction

9. The Need to Matter in Clinical and Counseling Settings: The Treatment Process of the Client-Therapist Relationship

Part IV Mattering in Life Contexts

10. Mattering at School

11. Mattering at Work

12. Mattering in the Community

Part V Knowledge Mobilization and Future Directions

13. The Psychology of Mattering: Knowledge Implementation Recommendations

14. The Psychology of Mattering: Issues and Future Directions