Older people remain underrepresented in translational studies, primarily due to the challenges associated with including aged animals. Their low survivorship, frailty status and heterogeneity hinder their use in longitudinal studies. Furthermore, social isolation, a prevalent issue among this population, is difficult to replicate in animals of advanced age. This study aims to evaluate the impact of social isolation on a cohort of surviving, aged animals in three different behavioral dimensions. A total of 37 C57BL/6J mice of both sexes were assessed in a longitudinal design over a three-month follow-up period, starting at 24 months of age. The performance across emotional, cognitive, and motor dimensions was evaluated using a behavioral battery. Animals were randomly assigned to either social isolation or grouped cages. We observed a high degree of performance heterogeneity within the cohort, with basal differences dependent on sex. Interestingly, the effects of social isolation appeared to be non-linear, as the magnitude of the impact varied depending on the test and dimension analyzed. A detailed analysis of age-related changes in C57BL/6J mice is necessary, requiring convergent validity across several tests. The scarcity of research and the complexity of ethological designs play a key role in this analysis. A comprehensive understanding of resilience and vulnerability in this context is crucial, underscoring the importance of social factors such as isolation and its effect on the aging process.