Affinity towards Diversity (ATD) is conceived as a tendency to prefer or liking diversity and variations in the constitution of bio-physical and social scenarios of everyday life environment (Corral-Verdugo et al, 2007). A number of studies developed by our research groups have shown that this dispositional variable correlates with sustainable behavior, which includes actions of preservation of the physical environment (pro-ecological behavior), as well as pro-social actions such as altruistic behaviors. In addition, ATD seems to be linked to dispositional correlates of sustainable orientation (i.e., predispositions leading individuals to appreciate the diverse and dynamic interdependencies characterizing human-nature interactions, and to adopting more sustainable personal lifestyles). The aim of this paper is to describe a series of studies developed in Mexico and Italy, showing how ATD is related to factors that the relevant literature considers psychological correlates of sustainability. Using a scale developed by our group we assessed the level of preference for social and biological diversity in different samples. The scale exhibited an acceptable level of internal consistency and it also showed construct validity. According to our studies, the correlates of ATD include austerity in consumption, future orientation, pro-environmental deliberation, feelings of indignation for environmental deterioration, affinity towards nature, the perception of pro-ecological norms, proecological self-presentation, altruism, tolerance, attitudes towards urban biodiversity and general proenvironmental behavior. Results of these studies suggest that humans have a certain degree of affinity for one crucial feature of ecology: diversity, and also that this affinity promotes pro-sustainability orientation. Implications of these studies for research on psychology of sustainability are discussed.