Older people are living longer and form a greater proportion of the population than ever before. By 2025, for the first time in history, 20% will be over 65 and 5.5% over 80. Each generation of older people (‘cohort’) differs from those that went before. They have different life experiences, expectations and views of the world. Their approaches to retirement, leisure, health, activity, nutrition and exercise differ from those of their parents’ generation, as do their ideas regarding how needs for care and support should be met, influenced perhaps by changes in families and in society. This research will firstly repeat, as closely as possible, a survey of older people carried out in North Wales 15 years ago, in order to ask two specific questions: how have older people’s networks of social relationships changed, in the face of great changes in social structures and families over this time period? And: has the extent of changes in memory and thinking ability at a given age reduced with general improvements in health, exercise and activity? This will involve interviewing 2500 people aged 65 and over twice, two years apart, so we can compare rates of change over time between the two cohorts. A further 2500 older people will be similarly interviewed twice in a different part of Wales, to develop a more varied composite picture. The combined sample of 5000 will enable us to look at a number of important issues, including: what makes some older people better able to cope with difficult life circumstances than others, to be resilient? Does being resilient help the person have greater well-being if changes in memory and thinking are experienced? There is some evidence that having a higher level of education, remaining active, physically and mentally, having a more active social life and being bilingual reduce the risk of changes in memory and thinking, and perhaps dementia, in later life. This study will be able to examine which of these factors are associated with fewer changes in memory and thinking, initially and over a two-year follow-up period. Some older people will also be asked to have a blood test, which will indicate levels of nutrition, which similarly may protect against changes in memory and thinking, and also be related to levels of activity. Interviewing 5000 older people on two occasions is a major undertaking. This study benefits from the methods used having been tried and tested in previous research. This includes the procedures for identifying the older people to be approached from General Practitioner lists; procedures for training interviewers and for carrying out the interviews; tests of memory and thinking; and the methods of recording and managing and analysing all the large amount of data generated. Large samples are needed in order to gain a better understanding of the changes in the experience of ageing. The core of the data can be shared with an on-going study using the same procedures in 3 sites in England – giving a combined sample of 12,500 older people for providing estimates of health and of levels of memory and thinking, and of mood. However, the study proposed here would importantly add consideration of aspects of personality such as resilience, a detailed analysis of networks of social relationships, evaluation of nutritional status, and the opportunity to study the effects of being bilingual on changes in memory and thinking in later life (as many as two-thirds of older people in the North Wales study area are bilingual). The study will provide more up-to-date information regarding ageing and older people, placing the individual in the context of their social relationships and of the wider communities in which they live. It will help governments and councils to plan more effectively for the future, and inform public awareness of the bigger picture of growing older today, drawing attention to possible ways of reducing risk factors and of developing resilience in the face of adversity.