Attachment in Adulthood -- This site, maintained by Phillip Shaver and colleagues, has the latest results from their research on adult attachment and its relation to emotions and well-being.
Emotion and Adult Personality Development -- This article in the American Psychological Association Monitor (the Association's newsletter) describes a study in which an aspect of personality -- how much a person smiles in yearbook pictures -- influences their later lives. It reflects one aspect of how personality develops over time.