This between groups experimental design study explores the relationship between executive functioning, dual task ability and socio-behavioural performance in healthy ageing. Case study methodology was also used to explore how these functions are affected by Alzheimer’s disease, and whether dual task ability and socio-behavioural ability are related as has been found in patients with a traumatic brain injury (Alderman, 1996; Foley et al., 2010). Twenty-five healthy younger adults, twenty-five older adults and three patients with Alzheimer’s disease were assessed on a dual task paradigm and a range of executive function and socio-behavioural tasks. Results showed a decline in executive function ability in the older group but no impairment in performance of the dual task or any of the socio-behavioural measures. Participants with Alzheimer’s disease showed impaired executive performance and a varying pattern of decline in socio-behavioural functioning but no impairment in dual task ability. These findings suggest that socio-behavioural functioning is not affected by healthy ageing but is affected by Alzheimer’s disease, and in these case studies socio-behavioural impairment was not found to be related to dual task decline.