1. The purpose of primate cognitive studies Bennett L. Schwartz and Michael J. Beran; 2. A history of primates studying primates David A. Washburn and Sarah G. Walters; 3. Genetic and environmental influences on Chimpanzee brain and cognition William D. Hopkins and Chet C. Sherwood; 4. The evolution of cognition in primates, including humans David A. Leavens; 5. State of the field: developmental primate cognition Eliza L. Nelson, Jacqueline Alvarez, Brenda Jimenez and Kasey Padron; 6. Current perspectives on primate perception Audrey E. Parrish and Christian Agrillo; 7. The comparative study of categorization J. David Smith, Brooke N. Jackson, Andres F. Sanchez, and Barbara A. Church; 8. Numerical cognition in non-human primates Sarah Jones and Jasmine Roman; 9. The natural history of primate spatial cognition: an organismic perspective Charles R. Menzel and Ken Sayers; 10. Progress and prospects in primate tool use and cognition Kathelijne Koops and Crickette Sanz; 11. Sequencing, artificial grammar, and recursion in primates Stephen Ferrigno; 12. The evolution of episodic cognition: the sense of time Gema Martin-Ordas; 13. Metacognition Victoria L. Templer; 14. Bridging the conceptual gap between inferential reasoning and problem solving in primates Josep Call; 15. The eyes have it: using non-invasive eye tracking to advance comparative social cognition research Lauren H. Howard and Elizabeth V. Lonsdorf; 16. Social cooperation in primates Stella R. Mayerhoff, Jhonatan M. Saldaña Santisteban and Sarah F. Brosnan; 17. Primate communication: affective, intentional, or both? Rafaela Heesen, Christine Sievers, Thibaud Gruber and Zanna Clay; 18. Theory of mind in nonhuman primates Laura S. Lewis and Christopher Krupenye; 19. A requiem for ape language research: the cognitive foundations of language Lisa A. Heimbauer and Mark A. Krause; 20. Primate empathy: a flexible and multi-componential phenomenon Jake S. Brooker, Christine E. Webb and Zanna Clay; 21. Replication and reproducibility in primate cognition research Benjamin G. Farrar, Christopher Krupenye, Alba Motes-Rodrigo, Claudio Tennie, Julia Fischer, Drew M. Altschul and Ljerka Ostojić; 22. Ethical considerations in conducting primate cognition research Stephen R. Ross, Jesse G. Leinwand, and Lydia M. Hopper; 23. Collaboration and open science initiatives in primate research Drew Altschul, Manuel Bohn, Charlotte Canteloup, Sonja J. Ebel, Daniel Hanus, R. Adriana Hernandez-Aguilar, Marine Joly, Stefanie Keupp, Miquel Llorente, Cathal O'Madagain, Christopher I. Petkov, Darby Proctor, Alba Motes-Rodrigo, Kirsten Sutherland, Anna Szabelska, Derry Taylor, Christoph J. Völter and Nicolás G. Wiggenhauser; 24. Studying primate cognition: from the wild to captivity and back Julia Fischer; 25. Do monkeys belong in the ape house? Comparing cognition across primate species Jennifer Vonk and Jared Edge.