PurposeRelying on information processing and attribution theories, which relate to the formation of leadership perceptions and attributes, the current study seeks to examine the relationship between demographic variables and principals' systems thinking (PST) in an integrated model. The present study purpose was threefold: first, the study seeks to examine whether attributions middle leaders make about PST may show substantial and systematic variance in a management team. Second, the study seeks to investigate the influence of principal–middle leaders’ relational demography variables (gender, education and tenure) (dis)similarity on middle leaders’ PST attribute. Finally, the study seeks to explore the moderating role of duration of principal- principal–middle leader acquaintance in the relationship of demographic (dis)similarity to PST.Design/methodology/approachData were collected from 305 dyads (middle leaders and their principals) from 101 schools. MANOVA analysis and hierarchical regression analyses were used to test the hypothesis.FindingsFindings showed that it is both appropriate and important to examine group-level effects when studying PST effects. Also, PST levels were higher in gender-similar relationships than in gender-dissimilar ones. Finally, duration of acquaintance was found to moderate the relationship between principal–middle leaders’ gender (dis)similarity and PST appraisal.Originality/valueFocusing on principal–middle leader relationships, which are explicitly relational, with a consideration for level relationships may potentially highlight the need to consider multiple levels of analysis in order to understand how PST attribution occurs. This focus can help us to capture the core of PST social dynamics among the dyad, as well as highlighting the distinction, if any, between in-groups and out-groups. Acknowledging that school faculty are motivated by their interpersonal relationships with their principals and how such relationships are contingent upon demography (dis)similarity and the duration of acquaintance between dyads may help to broaden the understanding regarding potential antecedents of middle leaders' PST attribution and its implication for school organizations.