This study investigates biases in systems thinking, utilizing the DSRP model to analyze cognitive complexity in written language. We tested three hypotheses regarding the prevalence of DSRP elements and patterns in both systems thinking-trained and untrained individuals. Our results confirmed that systems thinking commonly exhibits significant biases in relation to the ideal even prevalence of DSRP elements and patterns, with notable differences between systems thinking trained and untrained groups. While training positively impacts the efficiency of systems thinking, it shows a lack of influence on mitigating systems thinking biases. Our study highlighted a remarkable relationship between critical systems thinking and systems thinking efficiency and parallelism. It also revealed a pronounced lack of relational and perspectival patterns in our study cohort responses. The study contributes to the understanding of cognitive biases in systems thinking and suggests the need for more systematic integration of bias-awareness in systems thinking theories, training, and practice.