Does Age Matter? A Comparison of Personality Profiles in Adult and Older Patients with Cancer Using the Structural Analysis of Social Behavior (SASB)

Background/Objectives: This study aimed to examine personality profiles at the intrapsychic level (“Oneself”) in adult and older patients with cancer and to compare potential differences between these age groups. Methods: In this observational, cross-sectional comparative study, 273 patients with cancer (all disease stages) were categorized into two age groups: adults (40–64 years, n = 141) and older adults (≥65 years, n = 132). Personality was assessed using the Structural Analysis of Social Behavior (SASB) Form-A. Descriptive and inferential bivariate statistical analyses, including Chi-square tests and independent-samples t-tests, were performed to evaluate differences between the two age groups. To further examine the association between age group and SASB Cluster 1, a multivariable exploratory post hoc factorial General Linear Model (factorial GLM) was conducted. Results: Comparisons between adults and older adults revealed significant differences in socio-demographic backgrounds, with older patients being more frequently widowed and having lower educational attainment (both p < 0.001). Regarding personality dimensions, a significant difference was observed exclusively in SASB Cluster 1 (Autonomy-Assertive and Separating), with higher scores among older participants (4.4 vs. 3.9; p = 0.002). However, in the adjusted factorial GLM, the main effect of age group was no longer statistically significant (p = 0.054), and no significant two-way interactions emerged, including the age-group-by-education interaction (p = 0.222). This indicates that the initial unadjusted age-group association was attenuated after accounting for selected socio-demographic variables. No significant differences were found between the two groups in the remaining SASB Clusters. Conclusions: These findings caution against overestimating the role of chronological age as an isolated variable in psycho-oncological research. Personality differences in Cluster 1 co-occur with distinct cohort-specific and socio-demographic life-course profiles. Understanding how personality relates to shifting socio-demographic circumstances across the lifespan may support the development of more tailored, context-sensitive psycho-oncological interventions.