This thesis examines well-being among the very old and the factors believed to influence the three components of well-being called life satisfaction, positive affect and negative affect. It also examines activity patterns, the factors related to activity and the consequences of different types of activity for well-being. The study is part of the Kungsholmen project which involved all inhabitants aged 75 years and over, living in a specific part of the inner city of Stockholm. This thesis covers 105 subjects who were 90 years and older, scoring 24 points or above on the Mini-Mental State Examination. Well-being was assessed with the Positive and Negative Affect Schedule, the Life Satisfaction Index-B and the Life Satisfaction Index-Z.

Study I examined fife satisfaction among the very old and the factors believed to influence life satisfaction. Life satisfaction was slightly lower than in other studies, which involved samples of younger elderly. In addition, factors such as life events, activities, personality and social contacts were assessed in order to determine their relative influence on life satisfaction. The very elderly tended to have higher life satisfaction if they had an extraverted and emotionally stable personality, excellent subjective health, good social relationships, and if they did pleasurable activities. The factors associated with life satisfaction were also investigated qualitatively. With this approach we found out what the elderly themselves believe gives them life satisfaction, The quantitative and qualitative data came up with some factors in common (e.g., health, family contacts), but there were some differences as well.

Study II examined Positive Affect and Negative Affect among the very old and the factors, which might influence these. Results showed that Positive Affect and Negative Affect were virtually uncorrelated. Comparing the results with studies of younger age groups, Positive Affect appears to decrease with age, while Negative Affect shows no clear age trend. The very elderly tended to have higher Positive Affect during the past year if they had excellent health, an extraverted personality, a definite religious or non religious belief, lived with another person, had good social relationships, read a lot, were well educated and followed radio/TV news. They seemed to have higher Negative Affect during the past year if they scored high on neuroticism, had many adverse life events, did not read, and did not participate in group activities.

Study III examined activity patterns among the very old, the factors related to activity and the consequences for well-being. Activities over the previous day were rated for degree of intellectual, social and physical activity. This age group tended to have variable but relatively low activity levels over the day. Good health and not moving house were associated with greater intellectual activity. Extraversion and negative life events (such as death of close friend or family member) were associated with greater social activity, while younger age and better health were associated with greater physical activity. There was also a positive association between physical activity and well-being.

Study IV examined whether there is an association between objective health, measured as clinical medical diagnoses, and well-being among the very old. Subjects were given a medical examination covering eye diseases, osteoarticular diseases, cancer, cerebrovascular diseases, bronchopulmonary diseases, heart diseases, and endocrine diseases. The data suggested there is no association of physical diagnoses with well-being, despite the fact that a self-rated health measure was found to be associated with life-satisfaction.

Study V focused on the subjective experience of extreme old age for people scoring high and low respectively on well-being measures. The purpose was to illustrate and expand upon the quantitatively derived findings from previous studies using a qualitative approach inspired by Grounded Theory. The results suggested that 'outlook on life', 'social and emotional ties', engagement with the outside world' and 'physical capability' are important contributors to subjectively experienced well-being in this age group.

In these studies, personality emerged as the major determinant of well-being. In addition, the results showed that this age group has a low activity level which is affected by factors such as health, personality and life events.