This study investigates the relationship between key personality traits—Self-criticism, Dependence, Nurturance, and Emotional—and their influence on sustainability behaviours, using the FIKR (facet, insight, knowledge, and resilience). A sample of 409 individuals was analyzed to examine correlations between these traits and 19 other personality dimensions, alongside 4 demographic factors. The results reveal significant interactions, particularly how self-criticism negatively correlates with emotional expressiveness, and how nurturance and dependency are positively associated with communal and support-driven sustainability behaviours. The findings underscore the potential for tailoring environmental interventions to specific personality profiles, thereby enhancing individual engagement in sustainability efforts and contributing to the health of biological planetary systems. These insights can inform strategies for promoting long-term environmental stewardship by aligning personal traits with collective sustainability goals, thereby making a significant contribution to the field of environmental psychology.