Attachment, relationship satisfaction and personality were measured in a representative longitudinal sample of young adults over 8 years with three measurement occasions. The dynamics between personality and relationship development were examined in two groups: stable continuers (N = 133), who remained with the same partner, and relationship changers (N = 92), who ended their partnership and entered into a new relationship. Partnership satisfaction but not personality predicted relationship stability. Neuroticism and attachment quality were more stable in continuers than in changers. Cross-lagged analyses of personality and relationship quality revealed a more consistent pattern of reciprocal influences in stable relationships, showing that dynamic transactions between personality and relationship quality are more likely to occur in stable social environments. Copyright © 2006 John Wiley & Sons, Ltd.