Personal relationships: an introduction; Part I. Foundations for Studying Relationships: 1. The seven seas of the study of personal relationships research: historical and recent currents; 2. What is good and what is missing in relationship theory and research; 3. Navigating methodological trade-offs in close relationships research; 4. Analyzing cross-sectional and longitudinal data in close relationships; 5. Relationship typologies; Part II. Developmental Arc of Relationships: 6. Relationship initiation and growth; 7. The affective structure of marriage over time; 8. Divorce and post-divorce relationships; Part III. Relationships across the Lifespan: 9. Friendships in childhood; 10. Personal relationships in adolescence and early adulthood; 11. Close relationships in middle and late adulthood; Part IV. Individual Differences: 12. Personality in close relationships; 13. Attachment theory as a framework for studying relationship dynamics and functioning; 14. Gender and relationships; 15. The intimate relationships of sexual and gender minorities; Part V. Basic Processes: 16. Neuroscience of salutary close relationships; 17. Social cognition in romantic relationships; 18. Communication: basic properties and their relevance to relationship research; 19. The Roles of emotion in relationships; Part VI. Interactive Processes: 20. Self-disclosure in relationships: revealing and concealing information about oneself to others; 21. Social support in close relationships; 22. Understanding couple conflict; 23. Sexuality in personal relationships; Part VII. Threats to Relationships: 24. Lying and deception in close relationships; 25. Stress, dyadic coping, and social support: moving toward integration; 26. The universal threat and temptation of extradyadic affairs; 27. Aggression and violence in romantic relationships; 28. Acceptance, rejection, and the quest for relational value; 29. New ways of theorizing and conducting research in the field of loneliness and social isolation; Part VIII. Relational Quality: 30. Romantic love; 31. Relationship satisfaction; 32. Commitment processes in personal relationships; 33. Relationships and physical health; Part IX. Context: 34. Social networks and personal relationships; 35. Personal relationships and technology in the digital age; 36. Ethnicity, culture, and close relationships; Part X. Maintenance and Repair of Relationships: 37. Promoting healthy relationships; 38. Maintaining relationships; 39. Treating relationship distress; Part XI. Conclusion: 40. Whither relationship science? The state of the science and an agenda for moving forward.