Novel ideals of later life promoting active ageing have spread across the world influencing our perception of dementia as a condition that necessitates health prevention, self-management, and empowerment. Yet, little research has looked at the role that these new strategies play in maintaining a divide in the population between those who age ‘successfully’ by living an agentic and active later life, and those who ‘fail’ to do so due to irreversible impairments, dementia and frailty. Following four years of research, this thesis explores the presence of this divide in new technologies, interventions and policies for dementia using ethnography. 1) By exploring the motivations of healthy people ‘training their brain’ in the United Kingdom, it emphasizes how prevention reinforces the fear of dementia as an unwanted identity and leads to distinction from it by healthy individuals. 2) By looking at cognitive rehabilitation in memory clinics in Southern Europe, it presents how this therapeutic practice ascribes people with dementia in a trajectory of decline, separating them from ‘normal ageing’. 3) By studying an intervention to support independence in dementia in the United Kingdom, it reviews how this type of intervention prioritizes a dementia freed from its non-agentic aspects. 4) By looking at the perspective of experts and advocates with dementia, it presents the existence of different social positions among people with dementia. These case studies illustrating distinction, ascription and omission in interventions for dementia show how social positioning by agentic individuals represent a yet unconsidered source of exclusion for the most vulnerable and dependent people with dementia. This thesis therefore questions the capacity of current dementia strategies’ to address social exclusion and argues for the importance of tailoring solutions to reflect the different levels of agency and dependency that people in these positions have.