As the director of a 75-year-old study on adult development, waldinger has unprecedented access to data on true happiness and satisfaction long life.
Njengomqondisi wokucwaninga kweminyaka engama-75 ngentuthuko yabantu abadala, uWaldinger unokufinyelela okungakaze kubonwe ngaphambili kwedatha onenjabulo yangempela nokwaneliseka.